Hi and Help please!!

I have a test tomorrow first period in geometry and I am stumped on these two problems on the review sheet.

a) Find QD if QE=11+20and QD=400-10 _______________

a-2 a+3 Q E D

E is the midpoint

b) Angle 3 and 4 are supplementary. Find the measure of angle 3

m>3=78+360and m>4=360+ 32

y y-3

Thank you to anyone that can help me. I am so tired, I can't see straight!