Question

What number needs to be added to both sides of the equation in order to complete the square? x2−18x=17

Enter your answers in the boxes.

x^2−18x + __ =17 + __

Answer 1

81

Step-by-step explanation:

I took the test !

Answer 2

81

Step-by-step explanation:

The square (x -a)² is ...

... (x -a)² = x² -2ax +a²

You can see the constant term (a²) is the square of half the x-coefficient ...

... a² = (-2a/2)²

The square of half the x-coefficient in your equation is ...

... (-18/2)² = (-9)² = 81

So, your equation is ...

`x^(2)-18x+\boxed{81}=17+\boxed{81}`