(x+1) (2x-3) - (x-1) (x+2) =x² +7一定要有过程!
问题描述:
(x+1) (2x-3) - (x-1) (x+2) =x² +7一定要有过程!
答
(x+1) (2x-3) - (x-1) (x+2) =x² +7
(2x^2-x-3) - (x^2+x-2) =x² +7
x^2-2x-1=x² +7
-2x=8
x=-4
答
(x+1) (2x-3) - (x-1) (x+2) =x² +7
(2x^2-x-3) - (x^2+x-2) =x² +7
x^2-2x-1=x² +7
-2x=8
x=-4 谢谢,望采纳!
答
(x+1) (2x-3) - (x-1) (x+2) =x² +7
2x2-3x+2x-3-(x2+2x-x-2)= x² +7
2x2-3x+2x-3-x2-2x+x+2= x² +7
x²-2x-1= x² +7
-2x-1=7
-2x=8
X=-4