Equation of the line with given x- and y-intercept 
What is the equation of the line with 5 and -3 as x- and y-intercept, respectively?

Is the answer $y = \frac{3}{5}x - 3$?
I saw an example question online but I am not entirely sure with how you do this. Can anybody help?

There exists a general formula: if the  $x$ and $y$-intercepts are $a\ne 0$ and $b\ne 0$ respectively, the line has equation
$$\frac xa+\frac yb =1.$$
Apply it and rewrite it in the form $\; y=\dots$.
