I really really need help Idont understand it

Answer:
angle A and angle B both equal 150 degrees
Step-by-step explanation:
angle A and angle B are congruent
so you take both equations and equal them together
8x-10=3x+90
+10 +10
8x=3x+100
-3x -3x
5x=100
/5 /5
x=20
Now that you have that, you plug it into the equations. You only plug it into one because they are both equal
Angle A = 8(20)-10
8*20= 160
160-10= 150
Hope this helps :D