若a=5x+2y,b=2x+5y,且x

问题描述:

若a=5x+2y,b=2x+5y,且x

∵a=5x+2y,b=2x+5y
∴a-b=5x+2y-2x-5y=3x-3y=3(x-y)
∵x你确定正确?肯定正确