1/4(4x²+2x-8)-(x²+1/2x-1)
=x²+ (1/2)x - 2 - x²- (1/2)x +1
=x² - x²+ (1/2)x - (1/2)x - 2+1
=-11/4(4x²+2x-8)-(x²+2x-1)这道呢？1/4(4x²+2x-8)-(x²+2x-1)=x²+ (1/2)x - 2 - x²- 2x +1=x² - x²+ (1/2)x -2x - 2+1=(-3/2)x-1