已知x+3y=2010,求(x²+2xy—-3y²)÷(x-y)的值.

问题描述:

已知x+3y=2010,求(x&sup2+2xy—-3y&sup2)÷(x-y)的值.

化简得(x+3y)*(x-y)/(x-y)=x+3y=2010