不解方程X方-5X=3,求(X-1)(2X-1)-(x+1)方+1的值
问题描述:
不解方程X方-5X=3,求(X-1)(2X-1)-(x+1)方+1的值
答
X方-5X=3
所以:
(X-1)(2X-1)-(x+1)方+1
=2x^2-3x+1-x^2-2x-1+1
=x^2-5x-1
=3+1
=4