4(y-3)²-25(y²-4y+4)=0
4(y-3)²-25(y-2)²=0
[2(y-3)]²-[5(y-2)]²=0
[2(y-3)+5(y-2)] [2(y-3)-5(y-2)]=0
(2y-6+5y-10)(2y-6-5y+10)=0
(7y-16)(-3y+4)=0
7y-16=0 或 -3y+4=0
y1=16/7
y2=4/3
(x+2)(x-3)=6
x²-x-6=6
x²-x-12=0
(x-4)(x+3)=0
x-4=0 或 x+3=0
x1=4
x2=-3
(2x+1)(4x-2)=(2x-1)²
2(2x+1)(2x-1)-(2x-1)²=0
(2x-1)[2(2x+1)-(2x-1)]=0
(2x-1)(4x+2-2x+1)=0
(2x-1)(2x+3)=0
2x-1=0 或 2x+3=0
x1=1/2
x2=-3/2