SOLUTION: Factor: 4x(x-1)=15 So far I have 4x^2-4x-15=0 But when it comes to factoring i"m stuck. Is this correct so far?

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Factor: 4x(x-1)=15 So far I have 4x^2-4x-15=0 But when it comes to factoring i"m stuck. Is this correct so far?      Log On


   

Question 302579: Factor:
4x(x-1)=15
So far I have 4x^2-4x-15=0
But when it comes to factoring i"m stuck. Is this correct so far?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
So far so good. Now you need to learn how to factor.
multiply the first coefficient 4 (of 4x^2) times the constant (-15)
4(-15)=-60
We want factors of -60 that add up to the x coefficient (-4)
-60 1
-30 2
-15 4
-10 6
wait up -10 + 6 equal -4
4x^2-4x-15=0
separate -4x into two parts (Remember FOIL)
4x^2+6x-10x-15=0
It doesn't matter which order we put (-10x+6x) or (6x-10x)
2x*(2x+3)-5*(2x+3) remember - times + is -
(2x-5)*(2x+3)=0
FOIL
4x^2-10x+6x-15
4x^2-4x-15