计算-(x-5y)-(-3x+2y)
问题描述:
计算-(x-5y)-(-3x+2y)
答
原式=-x+5y+3x-2y
=(3x-x)+(5y-2y)
=2x+3y2(2x的2次方-5xy+3y的2次方)-3(3x的2次方-2xy-y的2次方),谁先算我选谁为满意答案并送他100财富值2(2x²-5xy+3y²)-3(3x²-2xy-y²)=4x²-10xy+6y²-9x²+6xy+3y²=9y²-4xy-5x²=(9y+5x)(y-x)