Answer:
x = 18
Explanation:
the sum of the interior angles of a polygon is
sum = 180° (n - 2) ← n is the number of sides
here n = 5 , then
sum = 180° × 3 = 540°
sum the 5 interior angles and equate to 540
3x + 23 + 95 + 7x - 4 + 90 + 9x - 6 = 540
19x + 198 = 540 ( subtract 198 from both sides )
19x = 342 ( divide both sides by 19 )
x = 18