Question

Solve each equation by completing the square.
8. x^2-6x=-4

9. x^2 +8 =6x

10. 2x^2-20x=8

11.x^2=24-4x

12. 10x + x^2 =42

13. 2x^2 + 8x -15 =0

Answer 1

completing the square is adding or subtracting the constant to the other side, then using (b/2)^2 to make it factorable.

Obviously doing all six of those is going to take too much time, so you should be able to do the rest. >.>

x^2-6x=-4
add the (b/2)^2
x^2-6x+9=-4
factor it
(x-3)(x-3)=-4
set each factor (in this case, both are x--3 so you only need to do it once because they're the same) equal to -4
x-3=-4
add +3 to both sides
x=-1