3x^2-8x+9-(4x^2-7x+16)-4(2x^2+9)

问题描述:

3x^2-8x+9-(4x^2-7x+16)-4(2x^2+9)

原式=3x²-8x+9-4x²+7x-16-8x²-36
=-9x²-x-43