Maths

(1)23+8y=12y+15
23-15=12y-8y
8=4y
4y=8
y=8/4
y=2

(2)23-8y=12y+15
23-15=12y+8y
8=20y
20y=8
y=8/20
y=2/5

(3)23+8y=12y15
你係咪打少咗啲嘢呢..?
如果冇:
23+8y=12y*15
23+8y=180y
23=180y-8y
23=172y
172y=23
y=23/172

(4)23-8y=12y-15
23+15=12y+8y
38=20y
20y=38
y=38/20
y=1>18/20
y=1>9/10

(5)23+8y= -12y-15
23+15= -12y-8y
38= -20y
20y= -38
y= -38/20
y= -1>18/20
y= -1>9/10

(6)23-8y= -12y+15
23-15= -12y+8y
8= -4y
4y= -8
y= -8/4
y= -2

(7)23+8y=-12y-15
23+15= -12y-8y
38= -20y
20y= -38
y= -38/20
y= -1>18/20
y= -1>9/10
呢條同第(5)條一樣...

(8)23-8y=-12y+15
呢條同第(6)條一樣...

(9)-23+8y=12y+15
-23-15=12y-8y
-38=4y
4y= -38
y= -38/4
y= -9>2/4
y= -9>1/2

(10)-23-8y=12y+15
-23-15=12y+8y
-38=20y
20y= -38
y= -38/20
y= -1>18/20
y= -1>9/10

(11)-23+8y=12y-15
-23+15=12y-8y
-8=4y
4y= -8
y= -8/4
y= -2

(12)-23-8y=12y-15
-23+15=12y+8y
-8=20y
20y= -8
y= -8/20
y= -2/5

(13)-23+8y= -12y+15
-23-15= -12y-8y
-38= -20y
20y=38
y=38/20
y=1>18/20
y=1>9/10

(14)-23-8y= -12y+15
-23-15= -12y+8y
-38= -4y
4y=38
y=38/4
y=9>2/4
y=9>1/2

(15)-23+8y= -12y-15
-23+15= -12y-8y
-8= -20y
20y=8
y=8/20
y=2/5

(16)-23-8y= -12y-15
-23+15= -12y+8y
-8= -4y
4y=8
y=8/4
y=2

1)y=2
2)y=2
3)y=23
90
4)y=-19
10
5)y=-19
10
6)y=-2
7)y=-19
10
8)y=-2
9)y=-19
2
10)y=-19
10

11)y=-2
12)y=-19
2
13)y=19
10
14)Y=19
2
15)y=2
5
16)y=2


e.g.1
2 is fraction

(1) y=2
(2) y=2/5
(3) [23+8y=12y-15?] y=2
(4) y=19/10
(5) y=19/2
(6) y=-2
(7) y=-19/10
(8) 同(6)有分別?
(9) y=-2
(10) y=19/10
(11) y=-2
(12) y=-2/5
(13) y=19/10
(14) y=-19/2
(15) y=2/5
(16) y=2