Inequalities

您好，我是 lop****** ，高興能解答您的問題。

the perimeter of the triangle = three times of the length of the equilateral triangle , and note that the perimeter of the triangle can't be zero or less than zero , then

0 < 3(y+3) < 45
0/3 < y+3 < 45/5
0 - 3 < y < 15 - 3
-3 < y < 12

Answer : The range of values of y is -3 < y < 12 .

y should also be > 3, since side cannot be negative.

圖片參考：http://i42.tinypic.com/10d5myw.png


http://i42.tinypic.com/10d5myw.png



2012-01-12 14:53:48 補充：
(y+3)+(y+3)+(y+3)<45 and y>-3
-3<12