已知:(x-y)²与√5x-3y-6互为相反数,求:√x²+2xy+y²的值

问题描述:

已知:(x-y)²与√5x-3y-6互为相反数,求:√x²+2xy+y²的值

(x-y)²>=0,√(5x-3y-6)>=0,
互为相反数,(x-y)²=0,x-y=0,x=y;
√(5x-3y-6)=0,5x-3y-6=0,5x-3x-6=0,2x=6x=3=y,
√(x²+2xy+y²)=√(x+y)²=√(3+3)²=6.