Question

If a + b = 7 and ab = 12, Then find the value of (a² + b²)
1. 49
2. 37
3. 25
4. 28

Answer 1

Correct Answer - Option 3 : 25

Given:

a + b = 7 and ab = 12

Formula Used:

(a + b)² = a2 + b² + 2ab

Calculation:

As, a + b = 7

Squaring both sides we get,

a2 + b2 + 2ab = 49 

and ab = 12

a2 + b2 + 2 × 12 = 49

⇒ a2 + b2 = 49 - 24 = 25

∴ The value of a2 + b2 is 25.