If (a - b) = 7 and ab = 9, then (a2 + b2) = ?

From the formula,(a – b)2 = a2 + b2 –2abWe get,= a – b = 7 and ab = 9By putting values, we get,72 = a2 + b2 - 2× 9= a2 + b2 = 49 + 18 = 67

Q18 of 95 Page 94

If (a - b) = 7 and ab = 9, then (a² + b²) = ?

From the formula,

(a – b)² = a² + b² –2ab

We get,

= a – b = 7 and ab = 9

By putting values, we get,

7² = a² + b² - 2× 9

= a² + b² = 49 + 18 = 67

(82)² – (18)² = ?

(197 × 203) = ?

If (a + b) = 12 and ab = 14, then (a² + b²) = ?

If x = 10, then find the value of (4x² + 20x + 25).