Patricia purchased x meters of fencing. She originally intended to use all ofthe fencing to enclose a square region, but later decided to use all of the fencing to enclose a rectangular region with length y meters greater than its width. In square meters, what is the positive difference between the area of the square region and the area of the rectangular region?
(1)xy=256
(2)y=4
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
假设width为m, then length=m+y
已知条件:m+m+y=2m+y=x/2, 求m(m+y)-x^2/16,
带入已知条件x^2/16=(2m+y)^2/4, 求的式子变为m^2+my-(4m^2+4my+y^2)/4, 抵消掉相同项只剩下-y^2/4, 只要知道y即可
【引用】
假设width为m, then length=m+y
已知条件:m+m+y=2m+y=x/2, 求m(m+y)-x^2/16,
带入已知条件x^2/16=(2m+y)^2/4, 求的式子变为m^2+my-(4m^2+4my+y^2)/4, 抵消掉相同项只剩下-y^2/4, 只要知道y即可
题目有的条件要列出,并统一求解-->新构成的长方形中的长比宽多y
假设长方形长为m, 宽为n,根据题干可以得1) m+n = x/2, 2) m-n=y
移向得到m=x/4 + y/2, n=x/4-y/2
求(x/4)^2-mn 把数字带进去发现可以把x消掉,变成y^2/4,所以只要知道y就可以知道答案
不可能吧x当知道了,要不1 2 有啥差别
这道题是把x当做已知数吗?否则,为什么不需要(1)和(2)一起。我得到的结果是x^2/4pai+x^/16-y^2/4
square region是正方形区域
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