Question

What number must you add to complete the square x2+6x=15

Answer 1

(x+3)² = 24 is the complete square.

Explanation:

We have given equation

x² + 6x = 15

We have to complete the square.

For this we split the second term of equation.

x²+(2)(3)(x) = 15

We have to add the square of 3 on both sides of equation.

So, the equation becomes:

x²+(2)(3)x+3²= 15 + 3²

(x+3)² = 15 + 9

(x+3)² = 24

This is the complete square of given expression.