Answer:
x=20
<B = 150
Step-by-step explanation:
The angles are alternate interior angles and when the lines are parallel, alternate interior angles are equal
8x-10 = 3x+90
Subtract 3x from each side
8x-10 -3x = 3x+90-3x
5x-10 = 90
Add 10 to each side
5x-10 +10 = 90+10
5x = 100
Divide by 5
5x/5 = 100/5
x = 20
<B = 3x+90
= 3*20 +90
= 60+90
= 150
