中一數學 方程 急 20點

1)
1.4y+1 = 3.6-0.6y
(1.4y+1-1 = 3.6-0.6y-1)
1.4y = 2.6-0.6y
(1.4y+0.6y = 2.6-0.6y+0.6y)
2y = 2.6
(2y/2 = 2.6/2)
y = 1.3
**透過左右同時加/減/乘/除(括號步驟),把同類的放在一起計算
快的話可以不寫( )的步驟,下面幾題我會把( )省略掉
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2)
2(6+p)+7p = 3
12+2p+7p = 3
12+9p = 3
9p = -9
p = -1
**先計算括號,把括號消去,再繼續以上步驟
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3)
3(2q-1) = 4(q+3)
6q-3 = 4q+12
2q-3 = 12
2q = 15
q = 15/2
**習慣以約簡至最盡的分數表示會比較好,而不是小數7.5,不過可能要視乎老師要求而定
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4)
5(4-r)-2(3r+10) = 22
20-5r-6r-20 = 22
-11r = 22
r = -2
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5)
90+8(s-5) = 3(6+4s)
90+8s-40 = 18+12s
50+8s = 18+12s
32+8s = 12s
32 = 4s
s = 8
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6)
4[15+10(m-1)] = 80+25m
4(15+10m-10) = 80+25m
4(5+10m) = 80+25m
20+40m = 80+25m
40m = 60+25m
15m = 60
m=4
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還有不明白的可以再問,我會補充

其實也是加減乘除就調在一邊，見括號就拆
1)
1.4y+1=3.6-0.6y
2y=2.6
y=1.3

2)
2(6+p)+7p=3
12+2p+7p=3
9p= -9
p= -1

3)
3(2q-1)=4(q+3)
6q-3=4q+12
2q=15
q=7.5

4)
5(4-r)-2(3r+10)=22
20-5r-6r-20=22
-11r=22
r= -2

5)
90+8(s-5)=3(6+4s)
90+8s-40=18+12s
-4s=-32
s=8

6)
4[15+10(m-1)]=80+25m
4(15+10m-10)=80+25m
60+40m-40=80+25m
15m=60
m=4

想問答案定問功課??.....

(1) 1.4y +0.6y = 3.6 - 1
-> 2y = 2.6
-> y = 1.8

(2) 12 + 2p +7p = 3
-> 9p = -9
-> p = -1

(3) 6q - 3 = 4q +12
6q - 4q = 12 + 3
2q = 15
q = 7.5

(4) 20- 5r - 6r -20 = 22
11r = -22
r = -2

(5) 90 + 8s - 40 = 18 + 12s
4s = 32
s = 8

(6) 60 + 40m - 40 = 80 + 25m
15m = 60
m = 4