有6絛數學唔識做(代數)(10分)

1) 2x＋10=20
　2x = 20-10
　2x = 10
　x = 5

2) 2y＋10=－20
　2y = -20-10
　2y = -30
　y = -15

3) 3x＋20=41
　3x = 41-20
　3x = 21
　x = 7

4) 3y－20=43
　3y = 43+20
　3y = 63
　y = 21

5) 4x＋30=78
　4x = 78-30
　4x = 48
　x = 12

6) -4y﹢30=78
　-4y = 78 - 30
　-4y = 48
　y = -12

1.2x+10=20
2x=20-10
2x=10
x=10/2
x=5

2.2y+10=-20
2y=-20-10
2y=-30
y=-30/2
y=-15

3.3x+20=41
3x=41-20
3x=21
x=21/3
x=3

4.3y-20=43
3y=43+20
3y=63
y=63/3
y=13


5.4x+30=78
4x=78-30
4x=48
x=48/4
x=12

6.-4y+30=78
-4y=78-30
-4y=48
y=48/-4
y=-12

1. 2x＋10=20
2x=20-10
2x/2=10/2
x=5

2. 2y＋10=－20
2y=一20+10
2y/2=一10/2
y=一5

3. 3x＋20=41
3x=41一20
3x/3=21/3
x=7

4. 3y－20=43
3y=43+20
3y/3=63/3
y=21

5. 4x＋30=78
4x=78一30
4x/4=48/4
x=12

6. －4y﹢30=78
一4y=78一30
一4y/4=48/4
一y =12
y=一12

1) 2X + 10 = 20
2X = 20-10
X = (20-10)/2
X = 5
2) 2Y + 10 = -20
2Y = -20-10
Y = (-20-10)/2
Y = -15
3) 3X + 20 = 41
3X = 41-20
X = (41-20)/3
X = 7

本想同你答埋其他的.但 呢D係最最基本的代數. 3 條足夠做EXAMPLE有餘, 餘下的,自已試吓做吧. 總之,所有野由"="的左面放到右面,或右面放到左邊都係將+ 變 - 或 - 變加. 努力D試下

1.2x=10
x=5
2.2y=-30
y=-15
3. 3x=21
x=7
4.3y=63
y=21
5.4x=48
x=12
6. -4y=48
y=-12

1. x=5
2. y=-15
3. x=7
4. y=21
5. x=12
6. y=-12