How to solve this system of equation

3-a=b
1/2b-3a=0

How do you solve this?

Thanks

If you are solving for 'a' you try to get the 'a' alone. For example:
3-a=b Subtract the 3 to get it to the other side.
-a=b-3 Get rid of the negative.
a = -b+3
Get it? If you are solving for 'b' you just do the same thing but get 'b' by itself.

Solve the first equation for a or b. Let's solve for a.

That yields -a=b-3
or: a=3+b

Then plug that into the second equation which gives you:
1/2b-3(3+b)=0

1/2b-9-3b=0

1/2b-3b=9 Solve this equation for b

Then plug that b into the first equation to get a

b = 6a = 3-a
7a = 3
a=3/7
b=18/7