问题
解答题
解方程:x(x+1)2-x(x2-3)=20+2(x+1)(x-1)
答案
x(x+1)2-x(x2-3)=20+2(x+1)(x-1),
化简得:(x3+2x2+x)-(x3-3x)=20+2(x2-1),
去括号得:x3+2x2+x-x3+3x=20+2x2-2,
移项合并得:4x=18,
解得:x=
.9 2
解方程:x(x+1)2-x(x2-3)=20+2(x+1)(x-1)
x(x+1)2-x(x2-3)=20+2(x+1)(x-1),
化简得:(x3+2x2+x)-(x3-3x)=20+2(x2-1),
去括号得:x3+2x2+x-x3+3x=20+2x2-2,
移项合并得:4x=18,
解得:x=
.9 2