1.The perimeter of a rectangle with dimensions 4 cm by x cm is 18 cm greater than that of a square.If they have equal areas,find
a)the length of a side of the square,
b)the value of x.
幫我做呢題數ＴＨＸ
2007-12-31 5:19 am
回答 (1)
2007-12-31 6:03 am
✔ 最佳答案
Let the length of a side of the square be y cm. That is, 4 + X + 4 + X = 4y + 18
2X + 8 = 4y + 18
2X = 4y + 10
X = 2y + 5……….(1)
Also,
4 * X = y * y……….(2)
Put (1) into (2), we get
4 (2y + 5) = y^2
8y + 20 = y^2
y^ - 8y - 20 =0
(y - 10) (y + 2) = 0
Y = 10 or y = -2 (rejected)
Y = 10 (cm.) (ans.)
Put y = 10 into (1), we get
X = 2 * 10 + 5
X = 25 (cm.) (ans.)
希望幫到你.
收錄日期: 2021-04-19 00:15:53
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071230000051KK03741