數學功課.要有步驟ar...help ME..急!!

1. 3xc-3x4=2c-25
3c-12=2c-25
3c-12+12=2c-25+12
3c=2c-13
3c-2c=2c-2c-13
c=-13

2. 5xd-5x6=3d
5d-30=3d
5d-30+30=3d+30
5d=3d+30
5d-3d=3d-3d+30
2d=30
2d/2=30/2
d=15

3. 5xx+5x3-4x3x+4x6=-2x+19
5x+15-12x+24=-2x+19
5x-12x+15+24=-2x+19
-7x+39=-2x+19
-7x+39-39=-2x+19-39
-7x=-2x-20
-7x+2x=-2x+2x-20
-5x=-20
-5x/-5=-20/-5
x=4

4. 4xx-4x6=2xx-2x1-20
4x-24=2x-2-20
4x-24=2x-22
4x-24+24=2x-22+24
4x=2x+2
4x-2x=2x-2x+2
2x=2
2x/2=2/2
x=1
5. 7xd+7x2=2d+44
7d+14=2d+44
7d+14-14=2d+44-14
7d=2d+30
7d-2d=2d-2d+30
5d=30
5d/5=30/5
d=6

6. 3xy-3x2-4x5+4x2y=7y-14
3y-6-20+8y=7y-14
3y+8y-6-20=7y-14
11y-26=7y-14
11y-26+26=7y-14+26
11y=7y+12
11y-7y=7y-7y+12
4y=12
4y/4=12/4
y=3

3(c-4)=2c-25
3c-12=2c-25
3c-2c= -25+12
c= -13

5(d-6)=3d
5d-30=3d
5d-3d=30
d=15

5(x+3)-4(3x-6)=-2x+19
5x+15-12x-24=2x+19
5x-12x-2x=19-15+24
9x=28
x=28/9

4(x-6)=2(x-1)-20
4x-24=2x-2-20
4x-2x=-2-20+24
2x=6
x=3

7(d+2)=2d+44
7d+14=2d+44
7d-2d=44-14
5d=30
d=6

如果係3(y-2)=4(5-2y):
3y-6=20-8y
3y+8y=20+6
11y=26
y=26/11
如果係3(y-2)-4(5-2y):
3y-6-20-2y
(3y-2y)+(-6-20)
y-26(依降序)
如依升序:
3y-6-20-2y
(-6-20)+(3y-2y)
-26+y

1. 3(c-4)=2c-25
3c-12 =2c-25
3c-2c = -25+12
c = -13

2. 5(d-6)=3d
5d-30 =3d
5d-3d =30
2d =30
d =15

3. 5(x+3)-4(3x-6)=-2x+19
5x+15-12x+24= -2x+19
5x-12x+2x = -15-24+19
-5x = -20
x = 4

4. 4(x-6)=2(x-1)-20
4x-24=2x-2-20
4x-2x= 24-2-20
2x= 2
x=1

5. 7(d+2)=2d+44
7d+14=2d+44
7d-2d = 44-14
5d=30
d=6

6. 3(y-2)-4(5-2y)
=3y-6-20+8y
=11y-26

1.
3(c-4)=2c-25
3c-12=2c-25
c=-13

2.
5(d-6)=3d
5d-30=3d
2d=30
d=15

3.
5(x+3)-4(3x-6)=-2x+19
5x+15-12x+24=-2x+19
-7x+39=-2x+19
20=5x
x=4

4.
4(x-6)=2(x-1)-20
4x-24=2x-2-20
4x-24=2x-22
2x=2
x=1

5.
7(d+2)=2d+44
7d+14=2d+44
5d=30
d=6

6.
3(y-2) = 4(5-2y) 唔知你係咪打錯題目
3y-6=20-8y
11y=26
y=26/11