Answer:
B. 4.5
Step-by-step explanation:
(6x + 42)° and (18x - 12)° are alternate interior angles. If line l is parallel to line m, therefore,
6x + 42 = 18x - 12
Solve for the value of x. Combine like terms.
6x - 18x = -42 - 12
-12x = -54
Divide both sides by -12
-12x/-12 = -54/-12
x = 4.5
Therefore, x = 4.5 would prove lines l and m are parallel to each other.