Jawabanmu

2014-09-11T08:33:26+07:00
1. -x+10=20
-x=20-10
-x=10
x=-10

2. -2x-7=13
-2x=13+7
-2x=20
x=-10

3. x-9=7
x=7+9
x=16
2014-09-11T08:33:46+07:00
=> -x+10=20
-x = 20 - 10
-x = 10
x = 10/-1
x = -10

=> -2x-7=13
-2x = 13 + 7
-2x = 20
x = 20/-2
x = -10

=> x-9=7
x = 7 + 9
x = 16