You shouldn't feel bad. If the test requires you to show the work, you would just lose points for not doing that. But on something like the SAT, where time can be critical, use any logical shortcut you can. When I taught a GED prep course I encouraged students to use any process of elimination they could, if they didn't know how to solve a problem. (Wrong answers aren't penalized.)
This is the first time I heard any of the math teacher on TH-cam define that you start with the inner most brackets and work your way outward. Very Good.!
You can guess -1 as it's the only answer, but as many have figured out, 9/4 = 3^2/2^2 or (3/2)^2. Multiplying powers you get (3/2)^4, which is the inverse of (2/3)^4 giving the value of (1). Hence, multiply by -1, and the result is, -1. Cool problem dealing with products of exponents.
As the two fractions are identical/opposite the result it has to be -1. It looks like the channel over explaining things assuming that most of the people cannot understand the concept. It deserves “Likes” anyway.
simple 2^4 is 16, 3 to the 4th is more challenging, but is 27 x 3 which is 81. First fraction is negative 16/81 9^2 is 81 and 4^2 is 16. Second fraction is 81/16. Therefore cross cancel and you are left with negative 1.
I did the math in my head before I realized just what I was looking at! Let's see, 2 to the fourth divided by 4 to the second, hmmm that's 16 divided by 16. Okay what about the 9 to the second divided by 3 to the fourth? That's 81 divided by 81! See we wind up with a negative 16 divided by 81 multiplied by 81 divided by 16 or negative 16 time 81 divided by 81 times 16. Sounds like a total of negative 1 to me. I seem to remember Teacher telling us to read the question several times. Makes sense. Thumbs UP!!
The answer is b) -1, not only because it is the only negative option, but because (2/3)^4 is the same as (4/9)^2 and thus everything cancels out to -1.
I get a little confused -as this seems to be contrary to pemdas : - (2/3)^4 * (9/4)^2 = - (2/3)^4 * (3/2)^4 = -1 . as I am doing multiplication before expinential ( 2/3)^4 * (3/2)^4 = 1. I have been looking at these equation/solutions ( college was decades ago ) and I wonder how many of my eng calculations went wrong from not thinking pendas ( not saying true - just suposition ).
Ok the answer is -1 but it took you more than 20 minutes to explain this simple problem. Perhaps you should go back to grade 5 to learn maths instead of making videos.
Has to be −1, since that's the only negative option.
Also, i did the calculation, because the above felt like cheating.
I don't understand WHY these stupid multiple choices are provided... You can calculate the answer or not.
I also looked for the negative answer.
You shouldn't feel bad. If the test requires you to show the work, you would just lose points for not doing that. But on something like the SAT, where time can be critical, use any logical shortcut you can. When I taught a GED prep course I encouraged students to use any process of elimination they could, if they didn't know how to solve a problem. (Wrong answers aren't penalized.)
@@Astrobrant2 Yeah, that's great if your aim is to teach pupils to pass exams.
@@dazartingstall6680 Did I imply that I was using it as a substitute for actual education?
This is the first time I heard any of the math teacher on TH-cam define that you start with the inner most brackets and work your way outward. Very Good.!
You can guess -1 as it's the only answer, but as many have figured out, 9/4 = 3^2/2^2 or (3/2)^2. Multiplying powers you get (3/2)^4, which is the inverse of (2/3)^4 giving the value of (1). Hence, multiply by -1, and the result is, -1. Cool problem dealing with products of exponents.
I appreciate the simplicity so the concept can be tested mentally.
Some people get confused and think the negative is somehow raised to a power and thus makes the answer a positive. That’s why he included it.
Without calculation, you can already see that the answer must be negative because the minus (-) sign is not in brackets.
As the two fractions are identical/opposite the result it has to be -1. It looks like the channel over explaining things assuming that most of the people cannot understand the concept. It deserves “Likes” anyway.
simple 2^4 is 16, 3 to the 4th is more challenging, but is 27 x 3 which is 81. First fraction is negative 16/81
9^2 is 81 and 4^2 is 16. Second fraction is 81/16. Therefore cross cancel and you are left with negative 1.
I did the math in my head before I realized just what I was looking at! Let's see, 2 to the fourth divided by 4 to the second, hmmm that's 16 divided by 16. Okay what about the 9 to the second divided by 3 to the fourth? That's 81 divided by 81! See we wind up with a negative 16 divided by 81 multiplied by 81 divided by 16 or negative 16 time 81 divided by 81 times 16. Sounds like a total of negative 1 to me. I seem to remember Teacher telling us to read the question several times. Makes sense. Thumbs UP!!
The answer is b) -1, not only because it is the only negative option, but because (2/3)^4 is the same as (4/9)^2 and thus everything cancels out to -1.
Thank you. My favorite is quadratic equations ❤
good one, thanks.
Sometimes giving multiple choice answers takes away the need to actually work anything out because, in this case, there is only one negative answer.
I get a little confused -as this seems to be contrary to pemdas : - (2/3)^4 * (9/4)^2 = - (2/3)^4 * (3/2)^4 = -1 . as I am doing multiplication before expinential ( 2/3)^4 * (3/2)^4 = 1. I have been looking at these equation/solutions ( college was decades ago ) and I wonder how many of my eng calculations went wrong from not thinking pendas ( not saying true - just suposition ).
Very nice. Order of operations FTW
Thank you
Or, saving minutes of writing or explaining, (a/b)^x = (a^x)/(b^x). Students should be learning that in this stage of their studies.
Deu -1, letra B..
Try BODMAS:BIDMAS.
-1.
b) -1
-1
-1
B-1
B
b) -1
Why isnt the negative sign inside the parenthesis? (-2/3) 4 that makes more sense to me. ok, I see the difference
sorry to be blunt, but that is the equation - when you see - to left of equation ( like - (2/3)^2 - that means -1 * (2/3)^2 ).
-1
no
I gotta ask... What's the purpose of this?
😂-1
Ok the answer is -1 but it took you more than 20 minutes to explain this simple problem. Perhaps you should go back to grade 5 to learn maths instead of making videos.
-1 is the ans.
Too freaking fast!!
b)-1
-1
-1
-1