请问怎样理解这道题的题意。谢谢！

maryland

A tailor trims 4 feet from opposite edges of a square piece of cloth, and 5 feet from the other two edges. If 120 square feet of cloth remain, what was the length of a side of the original piece of cloth?

请问：这里的4feet和5feet都是怎么trim的？ 如果能有效果图更好了。：）按照我的理解我没法算出它的答案20。

brigittew

[upload=jpg]uploadImages/20029251722146353.jpg[/upload]
my method (x-4)*(x-5)=120-> x^2-9x +20 -120=0--> x=10

tongxun

20算不出来。（x-4）（x-5）=120。

xulingyan

问题是把X＝10代进去验证不对啊

maryland

可是按照(x-4)(x-5)=120算，x也不等于10啊，而应该是介于15到16之间，但是答案全都是整数。我想我们在理解题意上是不是和ETS有些出入呢？

brigittew

[upload=jpg]uploadImages/200292522355524224.jpg[/upload]
（x-8)*(x-10)=120--->x=20

tongxun

yes, you are right. Because it is "4 feet from opposite edges ". the most important word I had missed is " edges"!
thanks.

maryland

I got it,too.
brigittew, thanks a lot! ^^