|4y+9|-3=0????????????????
回答 (5)
2008-08-31 10:39 am
✔ 最佳答案
l4y+9l=34y+9=3 or 4y+9=-3
so 4y=-6=>y=-32 or 4y=-12=>y=-3
2008-08-31 10:52 pm
| 4y + 9 | = 3
- 3 = 4y + 9 = 3
- 12 = 4y = - 6
y = - 3 , y = - 3 / 2
- 3 = 4y + 9 = 3
- 12 = 4y = - 6
y = - 3 , y = - 3 / 2
2008-08-31 6:02 pm
|4y + 9| - 3 = 0
|4y + 9| = 3
4y + 9 = ±3
4y + 9 = 3
4y = 3 - 9
4y = -6
y = -6/4
y = -3/2 (-1.5)
4y + 9 = -3
4y = -3 - 9
4y = -12
y = -12/4
y = -3
â´ y = -3 , -3/2 (-1.5)
|4y + 9| = 3
4y + 9 = ±3
4y + 9 = 3
4y = 3 - 9
4y = -6
y = -6/4
y = -3/2 (-1.5)
4y + 9 = -3
4y = -3 - 9
4y = -12
y = -12/4
y = -3
â´ y = -3 , -3/2 (-1.5)
2008-08-31 5:46 pm
|4y+9|=3
(4y+9)^2=9
16y^2 + 72y+ 81 - 9 = 0
16y^2 + 72y + 72 = 0 (/8)
2y^2 + 9y + 9 = 0
y = -3 or y = -1.5
(4y+9)^2=9
16y^2 + 72y+ 81 - 9 = 0
16y^2 + 72y + 72 = 0 (/8)
2y^2 + 9y + 9 = 0
y = -3 or y = -1.5
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