先化简,再求值:(5x+3)(5x-3)-7x(3x-1)-(2x-1)^2 当x=-1/11时

问题描述:

先化简,再求值:(5x+3)(5x-3)-7x(3x-1)-(2x-1)^2 当x=-1/11时

(5x+3)(5x-3)-7x(3x-1)-(2x-1)^2
=25x^2-9-21x^2+7x-4x^2+4x-1
=11x-10

x=-1/11代入
原式=-1-10=-11

原式=25x²-9-21x²+7x-4x²+4x-1
=11x-10
=-11

(5x+3)(5x-3)-7x(3x-1)-(2x-1)^2
=25x² -9-21x²+7x-4x²+4x-1
=11x-10
=-1/11x11-10
=-1-10
=-11
如果本题有什么不明白可以追问,