90. The measure of an inscribed angle is half of that of the measure of its arc, and the measure of the angle corresponding with arc a is 45. 45*2 is 90, so 90 is the measure of arc a.
<span>"Simplifying
0.2y = 0.5x + 0.1
Reorder the terms:
0.2y = 0.1 + 0.5x
Solving
0.2y = 0.1 + 0.5x
Solving for variable 'y'.
Move all terms containing y to the left, all other terms to the right.
Divide each side by '0.2'.
y = 0.5 + 2.5x
Simplifying
y = 0.5 + 2.5x"</span>