Answer:
118
Step-by-step explanation:
AB and CD are parallel lines
∠ ABC + ∠DCB = 180 {Co- interior angles are supplementary}
3n - 47 + n + 7 = 180
3n + n - 47 + 7 = 180 {Combine like terms}
4n - 40 = 180
Add 40 to both sides
4n = 180 + 40
4n = 220
Divide both sides by 4
n = 220/4
n = 55
∠ABC = 3n - 47 = 3*55 - 47
= 165 - 47
∠ABC = 118
