Answer:
The answer would be 150 degrees.
Explanation:
When looking at the problem you can see that you have two parallel lines and a transversal. Since the two lines are parallel, this allows alternate interior angles to form, i.e. <A and <B.
Since angle A and B are alternate interior angles, you can now set the two equal to each other.
So, in order to find out what x equals, you have to set the two equations equal to each other.
8x-10=3x+90
Next, solve the new equation.
8x-10=3x+90
Add 10 to both sides.
8x=3x+100
Subtract 3x from both sides.
5x=100
Divide both sides by 5 and you'll get your answer.
x=20
Now that you know what x equals, you can substitute it into the equation for B.
<B= 3(20)+90
60+90= 150
<B=150 degrees
That gives you your answer of <B = 150 degrees.
To check your work you can also substitute x into the equation for <A.
<A= 8(20)-10
160-10= 150
<A=150 degrees.
Therefore, you have just proved that the answer is 150 degrees.