Answer:
b=4
Explanation:
since you have a straight line with 3 supplementary angles. One is given, one is 90⁰, and the other is an equation.
If we add 53 and 90:
53+90=143
we know that the line is a 180⁰.
So we will subtract 143 from 180.
180-143= 37
The equation states that (9 x b + 1) is equal to the angle which is 37. So we will equal 37 to the equation.
37= 9b+1
And now we solve for b.
We minus 1 on both sides.
37-1=9b
36= 9b
The we divide both side by 9
36/9 = 9b/9
4 = b
And that is how we find b.