Two parallel lines, m and n, are cut by a transversal, t, as shown in the figure below.

Answer:
C
Step-by-step explanation:
∠2 and ∠7 are alternate interior angles
alternate interior angles are congruent meaning ∠2 ≅ ∠7
we have ∠2 = 2x + 7 and ∠7 = 3x - 13
hence, 2x + 7 = 3x - 13
==> add 13 to both sides
2x + 20 = 3x
==> subtract 2x from both sides
20 = x
now to find the measure of ∠7 we plug in the value of x
∠7 = 3x - 13
==> plug in x = 20
∠7 = 3(20) - 13
==> multiply 3 and 20
∠7 = 60 - 13
==> subtract 13 from 60
∠7 = 47