SOLUTION: Hello. I am stumped on a homework assignment. I have to solve a quadratic equation using two methods. I have solved the equation using factoring and now have to figure out how to s

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Question 395690: Hello. I am stumped on a homework assignment. I have to solve a quadratic equation using two methods. I have solved the equation using factoring and now have to figure out how to solve it by completing the square method. The equation I have is z^2+z-2=0. Any help would be greatly appreciated.
Thank you.
Found 2 solutions by Alan3354, ewatrrr:
Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website!
I have solved the equation using factoring and now have to figure out how to solve it by completing the square method. The equation I have is z^2+z-2=0
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z^2+z-2=0
z^2+z = 2
a = 1, b = 1, c = -2
c has to be (b/2a)^2 = (1/2)^2 = 1/4
Add 1/4 to both sides
z^2 + z + 0.25 = 2.25
(z + 0.5)^2 = 1.5^2
z + 0.5 = � 1.5
z = -2, 1

Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website!

Hi
z^2 + z -2=0 |factoring (z+2)(z-1)=0 z = {-2,1}
z^2+ z - 2=0 |completing the square
(z+ 1/2)^2 - 1/4 - 2 = 0
(z+ 1/2)^2 -9/4 = 0
(z + 1/2)^2 = 9/4
z + 1/2 = � 3/2 |taking sqrt of both sides
z = -4/2 = -2
z = 2/2 = 1
z^2 + z -2=0

x = {-2,1}