解方程 (x-1)的平方-2(x-1)=15 过程

---

(x-1)的皮吵平方燃悄侍-2(x-1)=15
(x-1)²运枯-2(x-1)-15=0
(x-1-5)(x-1+3)=0
(x-6)(x+2)=0
x1=6 x2=-2

---

设x-1=y
原方粗神程岩悄亏变为：y2-2y=15
y（y-2）=15
y1=5，运斗y2=-3
x-1=5，x=6
x-1=-3，x=-2

---