If, when you divide by you get a remainder of , then .
So you have:
.
Simplify and solve these equations simultaneously for and .
so i get 4+2a+b=0(1) and 1-a+b=18(2)
then i make 1-a+b=18(times by 2) which is 2-2a+2b=36(3)
by elimination method
(3)+(1)
6+3b=36
3b=30
b=10
sub b=10 into (1)
4+2a+10=0
2a=-14
a=-7
so i get 4+2a+b=0(1) and 1-a+b=18(2)
then i make 1-a+b=18(times by 2) which is 2-2a+2b=36(3)
by elimination method
(3)+(1)
6+3b=36
3b=30
b=10
sub b=10 into (1)
4+2a+10=0
2a=-14
a=-7