Question 269446: I need to factor and solve by using the principle of zero theory
(x+3)(x-9)= -13
Please help! Found 2 solutions by stanbon, drk:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! I need to factor and solve by using the principle of zero theory
(x+3)(x-9)= -13
Expand the left side:
x^2 -6x - 27 = -13
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Rearrange:
x^2 -6x -14 = 0
Quadratic formula:
x = [6 +- sqrt(36 - 4*-14)]/2
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x = [6 +- sqrt(92)]/2
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x = [6 +- 2sqrt(23)]/2
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x = 3 + sqrt(23) or x = 3 - sqrt(23)
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Cheers,
Stan H.
You can put this solution on YOUR website! here is the original problem
(i)
step 1 - foil out the left side to get
(ii)
step 2 - set the equation = 0 to get
(iii)
step 3 - factor if possible. IN this case, we cannot apply our factoring steps as usual, so we must use the quadratic as
or
and then
finally
(
