Answer:
x = 7
Explanation:
Alternate interior angles are equal. Alternate interior angles look like these two angles.
7x - 7 = 4x + 14 Add 7 to both sides
7x - 7 + 7 = 4x + 14+7 Combine
7x = 4x + 21 Subract 4x from both sides
7x-4x = 4x - 4x + 21 Combine
3x = 21 Divide by 3
3x/3 = 21/3 Do the division
x = 7