若(x+y-3)的平方+(12x-y-3)的绝对值=0,则x+2y=

问题描述:

若(x+y-3)的平方+(12x-y-3)的绝对值=0,则x+2y=

(x+y-3)的平方+(12x-y-3)的绝对值=0
所以x+y-3=0
12x-y-3=0
相加
13x-6=0
x=6/13
y=3-x=33/13
所以x+2y=6/13+66/13=72/13