supplementary angles add up to 180 degrees, meaning when put together they form a straight line.
if angle D is five times the measurement of angle E, you add D and E together so what you would do is divide 180 by 6.
180÷6= 30
so there you have the measurement of angle E. to get the measurement of angle D, you multiply E by 5. (E being 30)
30×5=150
to check and see if this is the correct measurement you simply add the two together.
150+30=180