Question

If 102 × 98 = x, then find the value of x. 
1. 9956
2. 9986
3. 9926
4. 9996

Answer 1

Correct Answer - Option 4 : 9996

Given:

102 × 98 = x

Formula Used:

(a – b) × (a + b) = a² – b²

Calculation:

102 × 98 = x

⇒ (100 + 2) × (100 – 2)

⇒ (100)² – (2)²

⇒ 10000 – 4

⇒ 9996

∴ The value of x is 9996.