教我做數學

3a-7 = 5/4 * (2-3a)
4* (3a-7) = 5 * (2-3a)
12a - 28 = 10 - 15a
12a + 15a = 10 + 28
27a = 38
a = 38 / 27 = 1又27分之11 #

第2題, 題目是否正確? (3-1)??

3/2 * (3b+2) - 1/6 * (3-1) = -3/2 (** -1又2分之一 = -3/2)
6 * (3b+2) - (3-1) = -9 (左右 x 6)
18b + 12 - 2 = -9
18b = -19
b = -19 /18 = -1又18分之1 #

2006-10-22 22:47:18 補充：
補充的題目又有問題: 請問是A) 2分之3 (如第一次題目), 還是B) 3分2 (如補充資料),A)3/2(3b+2)-1/6(3b-1)=-1 1/2 9(3b+2)-3b+1 = -927b + 18 -3b +1 =-924b = -28b=-7/6 = -1 1/6#B)2/3(3b+2)-1/6(3b-1)=-1 1/2 4(3b+2)-3b+1 = -912b + 8 -3b +1 =-99b = -18b=-2 #

3a-7 = 5/4 * (2-3a)
4* (3a-7) = 5 * (2-3a)
12a - 28 = 10 - 15a
12a + 15a = 10 + 28
27a = 38
a = 38 / 27 = 1又27分之11 #

第2題, 題目是否正確? (3-1)??

3/2 * (3b+2) - 1/6 * (3-1) = -3/2 (** -1又2分之一 = -3/2)
6 * (3b+2) - (3-1) = -9 (左右 x 6)
18b + 12 - 2 = -9
18b = -19
b = -19 /18 = -1又18分之1 #

is correct

1.
3a-7 = 5/4(2-3a)
3a-7 = 5/4(-1a)
3a-7 = -5/4a
3a = -5/4a+7
3a = 6 3/4
a = 6 3/4 / 3
a = 27/4 x 1/3
a = 9/4
a = 2 1/4

2.
3/2(3b+2) - 1/6(3-1) = -1 1/2
3/2(5b) - 1/6(2) = -1 1/2
15/2b - 4/6 = -1 1/2
45/6b - 4/6 = -1 1/2
41/6b = -1 1/2
b = -1 1/2 / 41/6
b = - 3/2 x 6/41
b = -9/41

ps 我諗岩掛~= =||
我5肯定呀~但如果你覺得岩既就試下啦~^^

2006-10-21 15:11:17 補充：
2.2/3(3b+2)-1/6(3b-1)= -1 1/2 2/3(5b)-1/6(2b) = -1 1/2 10/3b - 2/6b = -1 1/2 20/6b - 2/6b = -1 1/2 18/6b = -1 1/2

2006-10-21 15:12:03 補充：
b = -1 1/2 / 18/6b = -3/2 x 6/18b = -3/6b = -1/2也是5肯定既答案....= =||