Y=mx+c isn't an equation to solve. It's the slope-intercept formula for graphing lines.
y and x are the variables, and m and c are the constants.
As an example, the line y=4x+2 looks like this:
3.305
+1.7
5.005
Line up the decimal points and add like you usually would add.
5.005 is the answer.
Make a t diagram between two cars