Question

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

Answer 1

Answer:

(x+3)² = 24  is the complete square.

Step-by-step 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.

Answer 2

Answer:

To complete the square you must split the b term in half, then square that answer.

6 is the b term, half of 6 is 3, 3 squared is 9. You will add 9 to both sides of x^2 + 6x = 15

x^2 + 6x + 9 =  24