Let S be the value of the second expression; that is, the value we want to find. Add 2 times the first equation to the second equation. With some rearranging we have 1/(1+2x) + 2x/(1+2x) + 1/(1+2y) + 2y/(1+2y) + 1/(1+2z) + 2z/(1+2z) = 2 + S Combine like terms: (1+2x)/(1+2x) + (1+2y)/(1+2y) + (1+2z)/(1+2z) = 2 + S All three terms on the left-hand side are 1, so we have 3 = 2 + S. Thus S = 1.
We can set 1+2x=a or x = (a-1)/2 1+2y=b or y = (b-1)/2 1+2z=c or z = (c-1)/2 substituting x, y, z in the eqn we get x/a + y/b + z/c =1 (a-1)/2a + (b-1)/2b + (c-1)/2c = 1 (Multiply both sides by 2) (a-1)/a + (b-1)/b + (c-1)/c = 2 Now (a-1)/a = 1 - 1/a and so on so we get 3 - 1/a - 1/b - 1/c = 2 and 1 = 1/a +1/b +1/c
Eliminating the fractions in both equations also works nicely: (1) Multiplying the first equation with 2(1+2x)(1+2y)(1+2z) yields 2x(1+2y)(1+2z) + 2y(1+2x)(1+2z) + 2z(1+2x)(1+2y) = 2(1+2x)(1+2y)(2+2z). Although this looks like a monster, it can be tamed after you (2) multiply the second equation with (1+2x)(1+2y)(1+2z). The second equation becomes (1+2y)(1+2z)+(1+2x)(1+2z)+(1+2x)(1+2y) = A(1+2x)(1+2y)(1+2z). (3) Taming these monster expressions is done by adding both equations together. The result is 3(1+2x)(1+2y)(1+2z) = (2+A)(1+2x)(1+2y)(1+2z). The parenthesis with x,y and z cancel out and we have the result 3 = 2+A and finally A=1.
Third method here. Let A= the required function and subtract each fraction from 1 3-A=1-1/(2x+1) + 1-1/(2y+1) + 1-1/(2z+[) 3-A=2(LHS of the first equation =1) 3-A=2*1 A=1
Let S be the value of the second expression; that is, the value we want to find.
Add 2 times the first equation to the second equation. With some rearranging we have
1/(1+2x) + 2x/(1+2x) + 1/(1+2y) +
2y/(1+2y) + 1/(1+2z) + 2z/(1+2z)
= 2 + S
Combine like terms:
(1+2x)/(1+2x) + (1+2y)/(1+2y) + (1+2z)/(1+2z) = 2 + S
All three terms on the left-hand side are 1, so we have 3 = 2 + S. Thus S = 1.
The best method so far!
We can set 1+2x=a or x = (a-1)/2
1+2y=b or y = (b-1)/2
1+2z=c or z = (c-1)/2
substituting x, y, z in the eqn we get
x/a + y/b + z/c =1
(a-1)/2a + (b-1)/2b + (c-1)/2c = 1 (Multiply both sides by 2)
(a-1)/a + (b-1)/b + (c-1)/c = 2
Now (a-1)/a = 1 - 1/a and so on
so we get 3 - 1/a - 1/b - 1/c = 2
and 1 = 1/a +1/b +1/c
1 is obviously an answer. The tricky part is showing that it is the only answer.
Eliminating the fractions in both equations also works nicely: (1) Multiplying the first equation with 2(1+2x)(1+2y)(1+2z) yields 2x(1+2y)(1+2z) + 2y(1+2x)(1+2z) + 2z(1+2x)(1+2y) = 2(1+2x)(1+2y)(2+2z). Although this looks like a monster, it can be tamed after you (2) multiply the second equation with (1+2x)(1+2y)(1+2z). The second equation becomes (1+2y)(1+2z)+(1+2x)(1+2z)+(1+2x)(1+2y) = A(1+2x)(1+2y)(1+2z). (3) Taming these monster expressions is done by adding both equations together. The result is 3(1+2x)(1+2y)(1+2z) = (2+A)(1+2x)(1+2y)(1+2z). The parenthesis with x,y and z cancel out and we have the result 3 = 2+A and finally A=1.
Directly used your second method (before seeing the video), which is very direct and elegant.
I tried a guess and check method and I putted the values for x,y,z=1 and same for the second equation and I got the 2nd equation equal to 1.
That's same I made ❤
please try this :
If aα^2+bα+c=5α^2+3α
aβ^2+bβ+c=5β^2+3β
& aγ^2+bγ+c=5γ^2+3γ
then find the value of a,b,&c
a=5,b=3,c=0
3th method:
I added -1-1-1=-3 to each terms and I found 1 also.
Or you can multiply the original equation by 2 then subtract 1 from each fraction. Result would be
-A=2-3
A=1
Third method here.
Let A= the required function and subtract each fraction from 1
3-A=1-1/(2x+1) + 1-1/(2y+1) + 1-1/(2z+[)
3-A=2(LHS of the first equation =1)
3-A=2*1
A=1
I did the second method but I MISCALCULATED IT and it became -0.5 instead as a solution so that's annoying
Let's put x = 1, y = 1, z = 1
1/3 + 1/3 + 1/3 = 1
Answer: 1
crazy, i've ever been to the answer but skipped
1.
1
ez
1