Question

2
(6) (5x-4)²
(d) (102) (98)​

Answer 1

Using the identity (x+a)(x+b) = x

2

+(a+b)x+ab

Writing 102 as 100+2 and 98 as 100−2

Hence (100+2)(100−2) = 100

2

+[2+(−2)]100+(2)(−2)

= 10000+(0)100−4

= 9996

The answer is 9996