SOLUTION: I am trying to complete the square. Here's what I did: x(2x+3)-1=0 x=2x+3+1=0+1 x=2x+4=1 x= (2,-2)

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: I am trying to complete the square. Here's what I did: x(2x+3)-1=0 x=2x+3+1=0+1 x=2x+4=1 x= (2,-2)      Log On


   

Question 324573: I am trying to complete the square. Here's what I did:
x(2x+3)-1=0
x=2x+3+1=0+1
x=2x+4=1
x= (2,-2)
Found 2 solutions by Fombitz, stanbon:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
No.
You have two equals signs in one equation.
Is your equation x%282x%2B3%29-1=0?
If so, then,
2x%5E2%2B3x-1=0
2%28x%5E2%2B%283%2F2%29x%29-1=0
Take (1/2) of the x coefficient and square it.
2%28x%5E2%2B%283%2F2%29x%2B9%2F16%29-1-2%289%2F16%29=0
2%28x%2B3%2F4%29%5E2-16%2F16-18%2F16=0
2%28x%2B3%2F4%29%5E2-34%2F16=0
2%28x%2B3%2F4%29%5E2=34%2F16
%28x%2B3%2F4%29%5E2=17%2F16
x%2B3%2F4=0+%2B-+sqrt%2817%29%2F4
x=-3%2F4+%2B-+sqrt%2817%29%2F4

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
I am trying to complete the square.
x(2x+3)-1=0
---
2x^2 + 3x - 1 = 0
2(x^2 + (3/2)x) = 1
----
Complete the square:
2(x^2 + (3/2)x + (3/4)^2) = 1 + 2(3/4)^2
---
2(x+(3/4))^2 = 1+9/8
---
2(x+(3/4))^2 = 17/8
---
(x+(3/4))^2 = 17/16
---
x+(3/4) = sqrt(17)/4 or x+(3/4) = -sqrt(17)/4
-----------------------------------------------
x = (-3+sqrt(17))/4 or x = (-3-sqrt(17))/4
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Cheers,
Stan H.