Question 30637: x^2+4x=32
Answer by sdmmadam@yahoo.com(530)   (Show Source):
You can put this solution on YOUR website! x^2+4x=32 ----(1)
The left side is of the form a^+2ab where a=x and b = 2
Therefore we require b^2 = 2^2 = 4 to complete the square.
Adding 4 to both the sides
x^2+4x+4 = 32+4
(x+2)^2 =6^2
Taking the square root
(x+2) = +6 or -6
That is x = -2+6 or x = -2-6
That is x = 4 or -8
Answer: x = 4 and x = -8
Verification: x = 4 in (1)
LHS = x^2+4x = 4^2+4X(4)= 16+16 = 32 = RHS
x = -8 in (1)
LHS = x^2+4x = (-8)^2+4X(-8)= 64-32 = 32 = RHS
Therefore our values are correct.
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