Answers

2014-11-13T13:12:38+08:00
2x+2y=14                              2(8)+2y=14
2x-2y=18                               16+2y=14
4x=32
                                    2y=14-16
4
   4                                       2y=-2

                                                y=-1
x=8
0
i thought 2x + 2y = 14 were solve separately from 2x - 2y = 18 :D
i haven't encounter this problem before.
i wonder why do you have to add the two? the type of arithmetic is not specify here. So i was confused
it was added to eliminate y. It's how elimination method works
thanks :D