Algebra
solve using the substitution method
3x-9y=3
6x-3y=-24
show work

Start by solving for x in the first problem:
3x=3+9y
x=1+3y
Then plug that into the second equation:
6(1+3y)-3y=-24
6+18y-3y=-24
15y=-30
y=-2
Then plug that back into first equation:
3x-9(-2)=3
3x+18=3
3x=-15
x=-5 
Then I would check your answer by plugging those into both equations:
3(-5)-9(-2)=3
-15+18=3
3=3 CHECK
6(-5)-3(-2)=-24
-30+6=-24
-24=-24 CHECK
 
So the answer is x=-5 y=-2