數學唔識做

2007-10-05 4:52 am
2=1/3(x-7)

2/3(x+5)=6

q-5/2 - 1/3 =2

3(p+1)/4 + 3=9

30=28 - 5(2-p)/2

回答 (9)

2007-10-05 5:18 am
✔ 最佳答案
2=1/3(x-7)
2X3=X -7 (左邊乘的話調過去變除 而 除除=乘)
6=x-7
6+7=x (減調去另一邊為減)
13=x

2/3(x+5)=6
X+5 = 6 x 3/2 (左邊乘的話調過去變除 而 除除=乘 乘除=除)
x+5=9
x=4

q-5/2 - 1/3 =2
q - 5/2 = 2+1/3 (通份母 2會幾2X 3/3 3/3 =1 所以唔會影響答案)
q-5/2 = 6/3+1/3
q-5/2=7/3
q=7/3+5/2(通份母 7/3會X2/2 5/2會X3/3 )
q=14/6+15/6
q=29/6

3(p+1)/4 + 3=9
3(p+1)/4=9-3
3(p+1)/4=6 ( 3(p+1)/4 可寫作 3/4 x (p+1) x=乘)
3/4x(p+1)=6
(p+1)=6x4/3 (上題解過點解會變 乖4/3)
p+1=8
p=8-1
p=7


30=28-5(2-p)/2
30-28=-5(2-p)/2
2=-5(2-p)/2
2x2=-5(2-p)
4=-5(2-p)
4=-5x2- (-5xp)
4=-20-(-5p) (負負得正)
4+20=5p
24=5p
p=24/5
2007-10-05 5:33 am
有步X

2=1/3x-7/3
13/3=1/3x
x=13

2/3x+10/3=6
2/3x=8/3
x=4

q=2+5/2+1/3
q=29/6

3p+3=(9-3)(4)
3p=21
p=7

2(2)=-10+5p
14=5p
p=14/5
2007-10-05 5:17 am
2=1/3(x-7)
2(3)=x-7
13=x
x=13

2/3(x+5)=6
x+5=9
x=4

q-5/2 - 1/3 =2
q=2+1/3+5/2
q=29/6

3(p+1)/4 + 3=9
3(p+1)/4 =9-3
3(p+1) =24
p+1 =8
p =7

30=28 - 5(2-p)/2
2= -5(2-p)/2
4= -5(2-p)
-0.8=2-p
p= 2.8
參考: ME
2007-10-05 5:13 am
第一條
2=1/3(x-7)
2*3(x-7)=1/3(x-7)*3(x-7)
6(x-7)=1
6(x-7)/6=1/6
x-7=1/6
x-7+7=1/6 + 7
x=7 1/6

第二條
2/3(x+5)=6
2/3(x+5)*3(x+5)=6*3(x+5)
2=18(x+5)
2/18=18(x+5)/18
1/9=x+5
1/9-5=x+5-5
1/9- 4 9/9=x
-4 8/9 = x


第三條
q-5/2-1/3=2
q-5/2-1/3+5/2+1/3=2+5/2+1/3
q=6/6+15/6+2/6
q=23/6
q=3 5/6

第四條
3(p+1)/4+3=9
3(p+1)/4+3-3=9-3
3(p+1)/4=6
3(p+1)/4*4=6*4
3(p+1)=24
3(p+1)/3=24/3
p+1=8
p+1-1=8-1
p=7

第五條
30=28-5(2-p)/2
30-28=28-28-5(2-p)/2
2=-5(2-p)/2
2*2=5(2-p)/2*2
4=5(2-p)
4/5=5(2-p)/5
4/5=2-p
4/5+p=2-p+p
4/5+p=2
4/5-4/5+p=2-4/5
p=1 5/5 - 4/5
p=1 1/5
參考: myself
2007-10-05 5:10 am
2 = 1/3 (x-7)
6 = x-7
13 = x
x = 13

2/3 (x+5) = 6
2 (x+5) = 18
2x + 10 = 18
2x = 8
x = 4

q - 5/2 - 1/3 = 2
6q - 5 (3) - 2 = 12 <--------全個乘6,為左清除個分母
6q - 15 - 2 = 12
6q = 29
q = 29/6

3(p+1)/4 + 3 = 9
3(p+1) + 12 = 36 <--------全個乘4,為左清除個分母
3p + 3 + 12 = 36
3p = 21
p = 7

30 = 28 - 5(2-p)/2
28 - 5(2-p)/2 = 30
56 - 5(2-p) = 60 <--------全個乘2,為左清除個分母
56 - 10 + 5p = 60 <------負負得正
5p = 14
p = 14/5
參考: 自己
2007-10-05 5:10 am
    2  =1/3(x-7)
   2除1/3=x-7
   6+7=x

2/3(x+5)=6
x+5 =6除2/3
x+5=4
x=-1

q-5/2 - 1/3 =2
q-5/2=2+1/3
q=2+1/3+5/2
q=2+2/6+15/6
q=5又5/6

3(p+1)/4 + 3=9
3(p+1)/4=6
3(p=1)=6*4
p+1=24除3
p=8-1
p=7

30=28 - 5(2-p)/2
30-28=-5(2-p)/2
2*2=-5(2-p)
4/5=p-2
2又4/5=p
p=2又4/5
參考: 我
2007-10-05 5:07 am
第一題: 2=1/3(x-7)
3(2)=x-7
6=x-7
x=13
第二題: 2/3(X+5)=6
X+5=6/(2/3)
X+5=4
X= -1
第三題唔知係q-5成個除2定係q-(5/2),計唔到俾你,之後o個幾題都係...
2007-10-05 5:04 am
1)13
2)4
3)29/8
4)15
5)14/5
2007-10-05 5:01 am
2=1/3x-7/3
13/3=1/3x
x=13

2/3x+10/3=6
2/3x=8/3
x=4

q=2+5/2+1/3
q=29/6

3p+3=(9-3)(4)
3p=21
p=7

2(2)=-10+5p
14=5p
p=14/5
參考: don;t copy me!


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