Answers

2016-03-19T21:57:05+05:30
            5x+8y+0=0

where , 
a=5
b=8
c=0
0
2016-03-19T21:57:12+05:30
5x=-8y
5x+8y=0
here a=5 b= 8 and c=0
1 5 1
so you meant than instead of then
yes
ohh .....
i dont care
and dont interfere me