Answers

2015-02-07T14:49:05+08:00
X²+4x=36-5x
x²+9x-36=0
x²+12x-3x-36=0
x(x+12)-3(x+12)=0
(x-3)(x+12)=0
x-3=0 ⇒x=3
       or
x+12=0⇒x=-12
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2015-02-07T18:50:19+08:00
X²+4x+5x-36=0 [transpose]

x²+9x-36=0  [add like terms]

(x-3) (x+12)=0  [factors of -36 that will be 9 {from 9x} if added, when multiplied, will be same with the equation]

x-3=0     x+12=0  [transpose]
x=3        x=-12
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