SAT Math : How to simplify binomials

Study concepts, example questions & explanations for SAT Math

varsity tutors app store varsity tutors android store varsity tutors ibooks store

Example Questions

Example Question #2162 : Sat Mathematics

If 〖(x+y)〗= 144 and 〖(x-y)〗= 64, what is the value of xy?

 

 

Possible Answers:

20

16

18

22

Correct answer:

20

Explanation:

We first expand each binomial to get x2 + 2xy + y2 = 144  and x2 - 2xy + y2 = 64. We then subtract the second equation from the first to find 4xy = 80. Finally, we divide each side by 4 to find xy = 20.

 

 

Learning Tools by Varsity Tutors