1.x(2x+7)=3(2x+7)
x(2x+7)-3(2x+7) =0
(2x+7)(x-3)=0
x=-7/2 x=3
2.3/2x²-4x=1
3x²-8x-2=0
x²-8x/3=2/3
x²-8x/3+16/9=2/3+16/9
(x-4/3)²=22/9
x=4/3+√22/3 x=4/3-√22/3
3.x（3x-4）-7=2（x²-2）+2x
3x²-4x-7=2x²-4+2x
x²-6x-3=0
x²-6x+9=12
(x-3)²=12
x=3+2√3 x=3-2√3