If a+b=8 and a2+b2=60, what is a2b2 ?

2 Answers
Feb 8, 2018

The answer is =4

Explanation:

(a+b)=8

and

a2+b2=60

Therefore,

(a+b)2=82=64

But,

(a+b)2=a2+b2+2ab

So,

64=60+2ab

2ab=6460=4

ab=42=2

and

a2b2=(ab)2=22=4

Feb 8, 2018

a2b2=4

Explanation:

given a+b=8

then (a+b)2=82=64

now (a+b)2=a2+2ab+b2

a2+2ab+b2=64

substitute a2+b2=60

60+2ab=64

2ab=6460=4

ab=42=2

square both sides

(ab)2=22

a2b2=4