The slope intercept form for equations will be
y = (2/3)x - 5/3 -----------------(1)
y = (-3/2)x + 7/2 ----------------(2)
As, you can see that slopes in both the equation are reciprocal and negative. That's why the lines are perpendicular to each other.
Hope this helps you. Do the work to make the equations in slope-intercept form. If you still have difficulty, we're there to help you out.