大家说这道题怎么做呢？？谢谢

If the average (arithmetic mean) of the assessed values

of x houses is $212,000 and the average of the assessed

values of y other houses is $194,000, what is the average

of the assessed values of the x+y houses?

(1) x+y=36

(2) x=2y

the average of the assessed values of the x+y houses212000x+194000y)/(x+y)

所以B是正确的，可以约掉未知数