Answers

2014-02-05T19:32:50+08:00
-y+7-9=3
-y=3+9-7
-y=5
y=-5
0
-y+7-9=3
-y=-7
-y=-7+9+3
-1(-y)=(5)-1
y=-5
-y=3-7+9
-y=5
y=-5
2014-02-05T23:16:14+08:00
Basic algebra
-y=3-7+9
-y=5
y=-5
0