(2x+1)平方+3(2x+1)=0
(2x+1)(2x+1+3)=0
(2x+1)(2x+4)=0
x=1/2,x=-2
x²-18=0
(x+3√2)(x-3√2)=0
x=-3√2,x=3√2
9x²-49=0
(3x+7)(3x-7)=0
x=-7/3,x=7/3
4(2x-1)²-25=0
(2x-1)²-25/4=0
(2x-1+5/2)(2x-1-5/2)=0
(2x+3/2)(2x-7/2)=0
x=-3/4,x=7/4
x²-2x+1=0
(x-1)²=0
x=1
(x-1)²-4(x-1)+4=0
(x-1-2)²=0
(x-3)²=0
x=3