One Algebra 2 question? I give medals!:)

Question

anonymous · Answer

Please write out the steps line by line for me, I really need the help!
Solve the system of equations.
3x-y=6
6x+y=21

anonymous · Answer

@uri can you help me with this problem?

anonymous · Answer

:( anyone...?

anonymous · Answer

Darn... Oh well.. Just turned it in blank. :/

anonymous · Answer

These are simultaneous equations. You need to take one away from the other or add them together so that one of the unknowns disappears. In your case there a -y in eq1 and a y in eq2, so if you add eq1 and eq2 together the ys will cancel out -y+y=0
3x-y+6x+y=6+21
9x=27
x=27/9
x=3

Then you can just substitute for x in either equations:
3x-y=6
3*3-y=6
3*3-6=y
y=3

There :)

anonymous · Answer

Thank you :)