Using graphs to solve equations

Question

After drawing the graph of $y=2x^2-3x-1$, I have to draw the graph of $2x^2-3x=0$, I know you have to rearrange to get the original equation but if there are no constants then how am I suppose to rearrange for the original and find what $y$ equals to then find the solutions of the graph?

Answer 1

hint

if $2x^2-3x=0$, then $y=-1$ , so you will look for intersection of your graph with the horizontal line whose equation is $y=-1$.