Question

Factorise 98 ( a+ b)${}^2$ - 2

• A. 2[(7a + 7b +1)(7a+7b+1)]
• B. 2[(7a + 7b -1)(7a+7b+1)]
• C. [(98a + 98b -2)(98a+98b+2)]
• D. [(49a + 49b -2)(49a+49b+2)]

Answer 1

The correct option is B

2[(7a + 7b -1)(7a+7b+1)]

Given 98 ( a+ b)${}^2$ - 2

Taking 2 common , we have

2[49(a+b)${}^2$ -1]
= 2[(7(a+b))${}^2$- 1]

using difference of squares ,we have
= 2[(7a + 7b -1)(7a+7b+1)]