Step-by-step explanation:
these are congruent angles. that means they are equal.
this is simply because when 2 lines intersect, they have the same angles (but mirrored left-right) above and below the lines. it must be, otherwise they are not straight lines.
so,
5x + 18 = 3x + 50
2x + 18 = 50
2x = 32
x = 16
