Answers

2014-08-12T18:55:16+08:00
=x+x+2+x+4-99
=3x+8-99
=3x-91
0
2014-08-12T20:16:11+08:00
Combine the same variables
 x+(x+2)+(x+4)-99
3x+8-99
3x-91
0