Answer:
8. X = 10.5 and 19. X = 5
Explanation:
8. You know that a triangle interior angles should add up to 180° so:
(10x - 11) + (3x - 2) + (3x + 1) = 180
180 = 16x - 12
168 = 16x
The you divide each side by 16:
168 ÷ 16 = 16x ÷ 16
X = 10.5
10. You know that a straight line equals 180° and interior angles add up to 180° so:
1st you do 180 - 151 = 29°
2nd (11x - 1) + (20x - 3) + (29) = 180
180 = 31x + 25
155 = 31x
The you divide each side by 31:
155 ÷ 31 = 31x ÷ 31
X = 5