已知x乘x-5x=14,求(x-1)(2x-1)-(x+1)(x+1)+1等于好多具体点撒,
问题描述:
已知x乘x-5x=14,求(x-1)(2x-1)-(x+1)(x+1)+1等于好多
具体点撒,
答
所求式=2x^2-3x+1-x^2-2x-1+1
=x^2-5x+1
=14+1
=15
答
(x-1)(2x-1)-(x+1)(x+1)+1
=2x^2-3x+1-(x^2+2x+1)+1
=x^2-5x+1
=14+1=15
答
原式=(2x²-x-2x+1)-(x²+2x+1)+1
=2x²-3x+1-x²-2x-1+1
=x²-5x+1
=14+1
=15