Question

If a + b = 9 and ab = 8 , find a2 + b2 .
a. 64
b. 83
c. 82
d. 65

Answer 1

Step-by-step explanation:

a=8 and b=1

ab=8×1=8

a+b=8+1=9

8square =8×8=64+1square=1×1=1

64+1=65

Answer 2

Answer:

a+b=9______(1)

ab=8______(2)

a²+b²=?

squaring equations (1)

(a+b)²=9²

a²+2ab+b²=9²

a²+b²+2(8)=81

a²+b²+16=81

a²+b²=81-16

a²+b²=65