Question

SAT question: If (a+b)^2 = 64 and a^2+b^2 = 40, what is the value of 4ab?

Answer 1

use the second relation, solve out one of them, and then replace after doing that biniomal exponent.

Answer 2

hi,
(a + b)^2 = a^2 + b^2 +2ab

hence a^2 + b^2 = 40

(a + b)^2 = 40 + 2ab
64 = 40 +2ab
2ab = 24
4ab = 48

hope this will help ya out !!!

Answer 3

thank you very much!

Answer 4

u r welcome