Question

If x + y = 12 and xy = 14, find the value of (x² + y²).

Answer 1

Given,

x + y = 12

Let’s square the both sides,

We get;

= (x + y)² = (12)²

= x² + y² + 2xy = 144

= x² + y² = 144 – 2xy

Also given,

xy = 14

= x² + y² = 144 – 2(14)

= x² + y² = 144 – 28

= x² + y² = 116

So, the value of (x² + y²) is 116.