大家说这道题怎么做呢？？谢谢

月影无痕

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

fhhrewr

谢谢!!! 原来是这意思. 我知道如何做题. 但"X+Y=36; X=2Y" 是什么意思? 是正确答案吗?你的答案"B"是哪来的?

daoying

x个房子的平均价值是212000，y个房子的平均价值是194000，问x+y个房子的平均价值是多少

fhhrewr

看不懂. 这题是什么意思?

girls

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