3x²-7=0
x²=7/3
x=-√21/3,x=√21/3
(2x-1)^2=9
2x-1=±3
x=(1±3)/2
x=-1,x=2
(x-2)(x-5)=-2
x²-7x+10=-2
x²-7x+12=0
(x-3)(x-4)=0
x=3,x=4