Question

211. If (a + b)2 = 64, (a - b)2 = 16, find the value of ab
+ 62​

Answer 1

Step-by-step explanation:

(a+b)2 = 64

Therefore , a+b = 64 /2

a+b = 32

a = 32 - b ...........( 1 )

(a-b)2 = 16

Therefore, a-b = 16 / 2

a-b = 8

a = b + 8 ..............( 2 )

Using equations (1) & ( 2 ) ,

32-b = b + 8

32- 8 = 2b

24 = 2b

Therefore, b = 24/2

b = 12 ; Therefore , a = 12+8

a = 20

Now , ab = 20 × 12

= 240

Therefore, ab = 240

ab + 62 = 240 + 62

= 302