Can you calculate the value of X? | (Rectangle) |

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  • เผยแพร่เมื่อ 3 ก.พ. 2025

ความคิดเห็น • 57

  • @jamestalbott4499
    @jamestalbott4499 10 วันที่ผ่านมา

    That was an awesome challenge! Thank you!

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Glad you enjoyed it! 😊
      You are very welcome!
      Thanks for the feedback ❤️🙏

  • @marioalb9726
    @marioalb9726 10 วันที่ผ่านมา +6

    ½bh = ½7h = A₂+7
    A₁+A₂ = A₂+7
    A₁ = 7cm² = ½bh= ½.x.7
    x = 2 cm ( Solved √)

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @Pippinn13
    @Pippinn13 9 วันที่ผ่านมา +2

    Let AD=a & AB=b
    We know ((a-x).(b-7))/2=7
    Expanding and simplifying
    ab-7a-xb+7x=14.
    We can see triangles DAB and PFB are similar, so the ratio of the sides are the same, so x/a=(b-7)/b -> xb=ab-7a.
    Substituting back into the last formula we get xb-xb+7x=14 -> 7x=14 -> x=2

  • @jtechnicalgaming7831
    @jtechnicalgaming7831 7 วันที่ผ่านมา

    Good question sir

  • @marcelowanderleycorreia8876
    @marcelowanderleycorreia8876 10 วันที่ผ่านมา +1

    Awesome question! Congratulations professor!! 👏👏

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Glad you liked it! 😊
      Thanks for the feedback ❤️🙏

  • @angeluomo
    @angeluomo 10 วันที่ผ่านมา +5

    Let FB=y and AD=h. The area of triangle FEB is yh/2 = 7 + xy/2, simplifying to yh=14+xy. The area of triangle ADB is ((7+y)*h)/2=7*(x+h)/2 + xy/2, simplifying to yh+7h=7x+7h+xy, or yh=7x+xy. Setting these two equations equal to each other, we get: 14+xy=7x+xy, or 14=7x, or x=2.

    • @allanflippin2453
      @allanflippin2453 10 วันที่ผ่านมา +1

      Yes, I used this approach as well and found it to be very easy. That is after I got over the idea of setting up three variables to solve for! Fortunately, solving for x is easy, although h and y are indeterminate.

    • @angeluomo
      @angeluomo 10 วันที่ผ่านมา

      @@allanflippin2453 True: h must be greater than 2 and y must be greater than 0. Otherwise, they can vary in the relationship: y=14/(h-2). A solution that sort of fits the scale would be h=5.5 and y=4; but there is no definitive information to determine that.

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @ultralegendgamer5956
    @ultralegendgamer5956 10 วันที่ผ่านมา +1

    Thats Sensational, Super excellent

    • @PreMath
      @PreMath  10 วันที่ผ่านมา +1

      Excellent!
      Glad to hear that!
      Thanks for the feedback ❤️

  • @JoanRosSendra
    @JoanRosSendra 6 วันที่ผ่านมา

    Muy ingenioso!
    Saludos

  • @zupitoxyt
    @zupitoxyt 10 วันที่ผ่านมา +2

    I appreciate Myself I got a very worthy teacher ❤

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Many thanks ❤️🙏
      Thanks for the feedback ❤️

  • @harikatragadda
    @harikatragadda 10 วันที่ผ่านมา +2

    [EPB] = ½EP*FB=7
    ∆DEP is Similar to ∆PFB.
    EP/ED=x/FB
    x= EP*FB/ED
    x = 14/7=2

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @jimlocke9320
    @jimlocke9320 10 วันที่ผ่านมา +1

    Solution by special case: The problem statement implies that the solution is the same regardless of the length of BF, as long as a valid figure is produced. Let BF = 7 and, if EP is treated as the base of ΔBEP, BF is the height. Area = 7 = (1/2)(EP)(BF) = (1/2)(EP)(7), so EP = 2. We note that ΔDEP and ΔBFP are similar but also have equal corresponding sides, DE = AF = 7 by opposite sides of a rectangle being equal, and BF = 7, so the triangles are congruent as well, and corresponding sides EP and PF are equal, so x = PF = EP = 2.
    On a multiple choice test, select x = 2 as your answer. On a test where you are not required to show your work, write x = 2 as your answer. If you are required to show your work and have solved the general case, the special case serves as a check that you have solved the problem correctly. If you have not solved the general case, solving the special case may lead you to a solution for the general case as follows: Let EP have length b (base of ΔBEP) and let BF have length h (height of ΔBEP, BF = h instead of 7). So Area ΔBEP = (1/2)bh = 7 and bh =14. By ratio of sides of similar triangles ΔDEP and ΔBFP, BF/DE = PF/EP, h/7 = x/b, x = bh/7 = 14/7 = 2. (Others posted basically the same solution earlier than I did.)

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Thanks for sharing your solution! 🙏

  • @JohnAlcaraz
    @JohnAlcaraz 6 วันที่ผ่านมา

    Let the triangle BEP have base EP=b and height FB=h. Note that AB = h+7 and AD = x+b. Since the area of BEP is 7=bh/2, we have b=14/h. Therefore AD = x + 14/h. We can show that triangles ABD and FBP are similar. Therefore AB/AD = FB/FP or (h+7)/(x+14/h) = h/x. Cross multiplying yields x(h+7) = (x+14/h)h, or xh+7x = xh+14. Thus 7x=14 or x=2.

  • @imetroangola17
    @imetroangola17 10 วันที่ผ่านมา +1

    *Solução:*
    Sejam FB = a e EP = b. Assim,
    [BPE] = ab/2= 7→ ab = 14.
    Os triângulos DAB e BPF são semelhantes, logo:
    AD/FP = AB/FB, como AD=EF, então:
    (x+b)/x = (7+ a)/a
    ax + ab = 7x + ax
    7x = ab, como ab=14, então:
    7x = 14
    *x = 2.*

    • @PreMath
      @PreMath  10 วันที่ผ่านมา +1

      Excellent!
      Thanks for sharing ❤️

  • @cyruschang1904
    @cyruschang1904 10 วันที่ผ่านมา +1

    L = the length of the rectangle
    The lower-right white triangle’s two legs = (L - 7 cm) & x
    The upper-left triangle is similar to the lower-right white triangle. The two legs of the upper-left white triangle = 7 cm & (7 cm)(x)/(L - 7 cm)
    The base and height of the yellow triangle = the short leg of the upper-left triangle and the long leg of the lower-right triangle
    [(7 cm)(x)/(L - 7 cm)] (L - 7 cm)/2 = 7 cm^2
    (7 cm)(x) = 14 cm^2
    x = 2 cm

    • @PreMath
      @PreMath  10 วันที่ผ่านมา +1

      Excellent!
      Thanks for sharing ❤️

    • @cyruschang1904
      @cyruschang1904 10 วันที่ผ่านมา

      @@PreMath Thank YOU 😊

  • @RK-tf8pq
    @RK-tf8pq 10 วันที่ผ่านมา +1

    Let us draw a perpendicular starting from point P and intersecting AD at a point G. So DG equal to EP. Let FB = y. From the area of the triangle EPB we can say that EP = 14/y, thus DG = 14/y. Since the triangles DGP and PFB are similar. DG/7 = x/y. Substituting DG =14/y we get 2/y = x/y, so x= 2

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @giuseppemalaguti435
    @giuseppemalaguti435 10 วันที่ผ่านมา +1

    FB=b,AD=h...h/(7+b)=x/b...bh=(7+b)x=7x+bx...=>bh-bx=7x...Area(triangolo)=b(h-x)/2=7...bh-bx=14=>x=14/7=2

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️🙏

  • @ОльгаСоломашенко-ь6ы
    @ОльгаСоломашенко-ь6ы 10 วันที่ผ่านมา +1

    ∆DEP подобен ∆BFP. DE=7, FB=y, S(EPB)=EP*FB/2=7, EP=14/y. DE/FB=EP/FP, 7/y=(14/y)/x. 7/y=14/(x*y). x=2.

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @himo3485
    @himo3485 10 วันที่ผ่านมา +1

    DFB=EFB
    DPF+PFB=EPB+PFB
    DPF=7cm^2
    x*7/2=7 x=2(cm)

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @JSSTyger
    @JSSTyger 10 วันที่ผ่านมา +1

    b/x=( b+7)/h
    bh/2-bx/2=7
    bh-bx=14
    bh=14+bx
    bh=(b+7)x
    14+bx = bx+7x
    14=7x
    x=2

    • @PreMath
      @PreMath  10 วันที่ผ่านมา +1

      Excellent!
      Thanks for sharing ❤️

  • @santiagoarosam430
    @santiagoarosam430 10 วันที่ผ่านมา +1

    EP=2*7/FB=14/FB---> EP/ED=FP/FB---> 14/FB*7=FP/FB---> FP=14/7=2=X.
    Gracias y un saludo cordial.

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @unknownidentity2846
    @unknownidentity2846 10 วันที่ผ่านมา +1

    Let's find x:
    .
    ..
    ...
    ....
    .....
    The right triangles BFP and ABD are obviously similar, so we can conclude:
    FP/AD = BF/AB
    FP/EF = BF/(AF + BF)
    FP/(EP + FP) = BF/(AF + BF)
    x/(EP + x) = BF/(AF + BF)
    x*(AF + BF) = BF*(EP + x)
    AF*x + BF*x = BF*EP + BF*x
    AF*x = BF*EP
    ⇒ x = BF*EP/AF = 2*(1/2)*BF*EP/AF = 2*(1/2)*EP*h(EP)/AF = 2*A(BEP)/AF = 2*7cm²/(7cm) = 2cm
    Best regards from Germany

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @wackojacko3962
    @wackojacko3962 10 วันที่ผ่านมา +1

    @ 2:12 is the very one reason I wear a Bowtie, because I like to project an aura of expertise and knowledge. Don't matter if the Bowtie is skewed a bit, it still symbolizes my deep reflection and intellect.😎

    • @PreMath
      @PreMath  10 วันที่ผ่านมา +1

      😀
      Thanks for the feedback ❤️

  • @DB-lg5sq
    @DB-lg5sq 2 วันที่ผ่านมา

    شكرا لكم على المجهودات
    يمكن استعمال
    BC=L
    BF=T
    T(L-x)=2×7
    tan(DBA)=x/T = L/(7+T)
    ......
    x/T = 2/T
    x=2

  • @marcgriselhubert3915
    @marcgriselhubert3915 10 วันที่ผ่านมา

    Here is something else: We name a = PE and b = FB. The area of the yellow triangle PBE is (1/2).a.b and is also equal to 7, so a.b = 14 and b = 14/a.
    Triangles DCB and DEP are similar, so DE/EP = DC/CB, so 7/a = (7+b)/(a+x), or 7/a = (7+(14/a))/(a+x), or 7.(a+x) = a.(7+(14/a)),
    Then we have 7.a +7.x =7.a +14, which gives that 7.x = 14, and so x = 2.

    • @phungpham1725
      @phungpham1725 10 วันที่ผ่านมา

      1/ Consider the yellow triangle: FBxEP = 14 (1)
      2/ Because of similarity: FB/7= x/EP --> FB= 7x/EP (2)
      3/ From (1) and (2) we have: 7x= 14
      --> x= 2 units😅😅😅

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Thanks for the feedback ❤️

  • @johnwindisch1956
    @johnwindisch1956 วันที่ผ่านมา

    Got it
    Using x/(FB) = (EP)/7
    And 1/2 • (EP•FB) = 7

  • @nenetstree914
    @nenetstree914 10 วันที่ผ่านมา +1

    2

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks for sharing ❤️

  • @Teamstudy4595
    @Teamstudy4595 10 วันที่ผ่านมา +2

    1st Comment

    • @PreMath
      @PreMath  10 วันที่ผ่านมา

      Excellent!
      Thanks ❤️🙏

  • @GreatnessStrikes
    @GreatnessStrikes 10 วันที่ผ่านมา

    *Hebrews 13:6*
    So we can confidently say "The Lord is my helper; I will not fear; what can man do to me?"
    *John 14:1*
    Let not your hearts be troubled. Believe in God; Believe also in me.
    *Proverbs 28:26*
    Whoever trusts his own mind is a fool, but he who walks in wisdom will be delivered.
    *Ephesians 2:8-9*
    8 For by grace you have been saved through faith, and this is not from you; it is the gift of God; 9 it is not from works, so no one may boast.
    *Romans 10:9*
    If you declare with your mouth, "Jesus is Lord", and believe in your heart that God raised him from the dead, you will be saved.
    *‭Romans 3:23-24*
    [23] for all have sinned and fall short of the glory of God, [24] and all are justified freely by his grace through the redemption that came by Christ Jesus.
    *John 14:6*
    Jesus answered, 'I am the way and the truth and the life. No one comes to the Father except through me.'
    *Acts 4:12*
    "Salvation is found in no one else, for there is no other name given under heaven by which we must be saved."

  • @GreatnessStrikes
    @GreatnessStrikes 10 วันที่ผ่านมา

    Jesus Christ is Lord. Turn to Christ before its too late

    • @SK-gs6xb
      @SK-gs6xb 10 วันที่ผ่านมา +2

      Wait, didn't the world end a couple of days back?

  • @LuisdeBritoCamacho
    @LuisdeBritoCamacho 10 วันที่ผ่านมา +1

    MY RESOLUTION PROPOSAL :
    01) First we must acknowledge that Triangle (DEP) is similar to Triangle (BFP).
    02) By the Law of Proportion we have :
    03) (EP / 7) = (X / BF) ; (EP * BF) = 7X
    04) As we can easily see : (EP * BF) = 14, because Triangle (BEP) = 7; where Base = EP and height = BF. So : (EP * BF) = 14 sq cm
    05) So, 14 = 7X
    06) X = 14 / 7
    07) X = 2 cm
    Therefore,
    MY BEST ANSWER IS :
    X must be equal to: 2 Centimeters.

    • @PreMath
      @PreMath  10 วันที่ผ่านมา +1

      Excellent!
      Thanks for sharing ❤️