Answers

2014-09-03T17:47:32+08:00
-3[-2x-y]
=-3[-2(-4)-(5)
=-3[8-5]
=-3[3]
=-9
0
2014-09-03T19:59:01+08:00
-3l-2(-4)-(5)l
-3l8-5l
-3l3l
-9
1 5 1