Answers

2015-07-20T07:59:06+08:00
X²+5x+4=0
x²+5x=-4
(b/5)²=(5/2)²=25/4
x²+5x+25/4=-4+25/4
(x+5/2)(x+5/2) = -16/4+25/4
√(x+5/2)² = √9/4
x+5/2 = +-3/2
x+5/2=3/2 x+5/2=-3/2
x=3/2-5/2 x=-3/2-5/2
x=-2/2 or -2 x=-8/2 or -4
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