(2) 求下列三角形中三高之長，其
1.三邊為4x-3y+8=0, 12x-5y+8=0, 2x-y=0
maths problem1
2010-10-28 5:36 am
回答 (2)
2010-10-28 7:04 am
✔ 最佳答案
========================================================圖片參考：http://img594.imageshack.us/img594/6276/13071609.png
2010-10-27 23:04:11 補充：
http://img594.imageshack.us/img594/6276/13071609.png
2010-10-28 6:06 am
4x-3y+8=0 ......... (1)
12x-5y+8=0 ........(2)
2x-y=0 ...............(3)
From (3),
2x-y=0
y=2x ........... (4)
Sub (4) into (1),
4x - 3(2x) + 8 = 0
4x-6x+8=0
-2x+8=0
2x=8
x=4,
then y=2(4) = 8
Sub (4) into (2),
12x-5y+8=0
12x-5(2x)+8=0
12x-10x+8=0
2x+8=0
2x=-8
x=-4 (not reasonable)
Therefore, the length of the triangle is 8
12x-5y+8=0 ........(2)
2x-y=0 ...............(3)
From (3),
2x-y=0
y=2x ........... (4)
Sub (4) into (1),
4x - 3(2x) + 8 = 0
4x-6x+8=0
-2x+8=0
2x=8
x=4,
then y=2(4) = 8
Sub (4) into (2),
12x-5y+8=0
12x-5(2x)+8=0
12x-10x+8=0
2x+8=0
2x=-8
x=-4 (not reasonable)
Therefore, the length of the triangle is 8
收錄日期: 2021-04-24 10:32:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101027000051KK01284