化简4x的2次方-【7x的2次方-5x-3(1-2x+x的平方)】结果是?
问题描述:
化简4x的2次方-【7x的2次方-5x-3(1-2x+x的平方)】结果是?
答
4x^2-[7x^2-5x-3(1-2x+x^2)]
=4x^2-(7x^2-5x-3+6x-3x^2)
=4x^2-7x^2+5x+3-6x+3x^2
=-x+3