方程algebra

1.
x-6 = x-3/4
4x-24=x-3
3x=21
x=7

2.
2y+1/5 = 3-y...(全部乘5)
10y+1=15-5y
15y=14
y=15/14

3. 8x+ 3x-7/2=6...(全部乘2)
16x+3x-7=12
19x=19
x=1

4.
b/3-(5-b) = 3...(全部乘3)
b-15+3b=9
4b=24
b = 6

5.
x/3-x/2 = 1...(全部乘6)
2x-3x=6
-x=6
x = -6

6.
3/4y = 1-1/2y
3/4y+1/2y=1
5/4y=1
5=4y
y=5/4

[1]

x-6=x-3/4
x=3/4-6
x=-5+1/4

[2]

2y+1/5=3-y
3y=3-1/5
y=14/5/3
y=14/15

[3]

8x+ 3x-7/2《二份之三Ｘ減七》=6
11x=19/2
x=19/22

[4]

b/3《三份之b》-(5-b)=3
b/3-5+b=3
b+b/3=8
2b=24
b=12

[5]

x/3-x/2=1

2x/6-3x/6=1
-1x=6
x=-6

[6]

3/4y《四份之三y》=1-1/2y《二份之一y》
3/4y+2/4y=1
5/4y=1
5y=4
y=4/5

2006-10-30 21:34:38 補充：
第一題是(-5+1/4)

1.
x-6 = x-3/4
x-x = -3/4-6
so no solution

2.
2y+1/5 = 3-y
2y+y = 3-1/5
3y = 14/5
y = 14/15

3.
is it 8x+(3/2)x-7 = 6??
(8+3/2)x = 6+7
(19/2)x = 13
x = 26/19

or

8x+3x-7/2 = 6??
(8+3)x = 6+7/2
11x = 19/2
x = 22/19

4.
b/3-(5-b) = 3
b/3-5+b = 3
(4/3)b = 3+5
(4/3)b = 8
b = 6

5.
x/3-x/2 = 1
(1/3-1/2)x = 1
-1/6x = 1
x = -6

6.
3/4y = 1-1/2y
(3/4+1/2)y = 1
5/4y = 1
y = 4/5