解方程:(1)2(x+3)=x(x+3)(2)x-2根号5x+2=0 (3)(x+1)-3(x+1)+2=0

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解方程:(1)2(x+3)=x(x+3)(2)x-2根号5x+2=0 (3)(x+1)-3(x+1)+2=0
解方程:(1)2(x+3)=x(x+3)(2)x-2根号5x+2=0 (3)(x+1)-3(x+1)+2=0

解方程:(1)2(x+3)=x(x+3)(2)x-2根号5x+2=0 (3)(x+1)-3(x+1)+2=0
(1)2(x+3)=x(x+3) ==> 2(x+3)=x(x+3) ==> (x+3) * [2(x+3)-x)] = 0 ==> (x+3) * (x+6) = 0 ==> x = -3,-6 (2)x-2根号5x+2=0 ==> x-2√5x+2=0 ==> x = {2√5 ±√[(-2√5) - 4 * 1 * 2]} / 2 ==> x = (2√5 ±√12) / 2 ==> x = √5 ±√3 (3)(x+1)-3(x+1)+ 2=0 ==> [(x+1) - 2] * [(x+1) -1] = 0 ==> (x-1) * x = 0 ==> x = 1,0