how would you solve a problem like this

Do you have more questions to it? Or maybe your teacher wants you to graph it?

If you want to graph it you need to find at least 2 points first. For example

f(x)=3x+3 is the same as y=3x+3

Pick any two numbers to "plug in" for "x" to get "y" just like this:

for x=1, y=3(1)+3=6 1st point is (1,6)

for x=2, y=3(2)+3=9 2nd point is (2,9)

(you can pick whatever you want for "x" )

now when you have to points you can put them on the graph and draw a line thru them. This will be a line with a linear equation f(x)= 3x+3