解方程 15點@v@

1. 17=8+4y-11
4y=17-8+11
4y=20
y=5

2. 7m-6=m
7m-m=6
6m=6
m=1

3. -9a=30+a
-9a-a=30
-10a=30
a=-3

4. 8z-5+3z=28
8z+3z=28+5
11z=33
z=3

5. 14u+6=2u-6
14u-2u=-6-6
12u=-12
u=-1

6. 23-r=7r-9
7r+r=23+9
8r=32
r=4

7. 7k+7b-2k+3
=7b+5k+3

8. 5y-6u+7u-y
=4y+u

1.2[例式題]
1. 4x-z+4z
= 4x +(4z-z)
= 4x + 3z

2. w+4j-j+8w
=(8w+w) + (4j-j)
= 9w + 3j


2011-10-03 20:08:15 補充：
輝輝的例式題第2題錯了,
8w+w該是9w,而不是7w.

hi me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

1) 17=8+4y-11
17=4y-3
20=4y
y=5

2) 7m-6=m
6m-6=0
6m=6
m=1

3) -9a=30+a
-10a=30
a=30/-10=-3

4) 8z-5+3z=28
11z-5=28
11z=33
z=33/11=3

5) 14u+6=2u-6
14u-12=2u
12u-12=0
12u=12
u=1

6) 23-r=7r-9
23=8r-9
32=8r
r=4

7) 7k+7b-2k+3
=(7k-2k)+7b+3
=5k+7b+3

8) 5y-6u+7u-y
=(5y-y)+(7u-6u)
=4y+u

1.2[例式題]
1. 4x-z+4z
= 4x +(4z-z)
= 4x+ 3z

2. w+4j-j+8w
=(w+8w) + (4j-j)
= 7w +3j