Question

9x^2-12x+5=0
Solve quadratic equation by completing the square.

Answer 1

i have an idea but its just not working

Answer 2

Move non-x term to the right
9x^2 -12x = -5

Divide by coefficient of x^2
x^2 -1.3333x = -(5/9)

Get coefficient of x, divide by 2 then square it
-1.3333 / 2 = -0.6666666667
(-0.6666666667)^2 = 0.4444444444

Add this to both sides

x^2 -1.33333x + .44444 = -4.5555555556

mutiplying both sides by -1

-x^2 + 1.333333x = 4.555555

take square root of both sides

Answer 3

My teacher says to keep in fraction form but this looks right thanks!

Answer 4

Okay - the answers by the way are:

x = 1.6667
x = -0.33333

using quadratic formula

Answer 5

thanks a lot!