Answer:
x = 4
Explanation:
If line A is parallel to line B, therefore,
9x + 4 = 5x + 20 (alternate interior angles theorem)
Solve for x. Collect like terms together
9x - 5x = -4 + 20
4x = 16
Divide both sides by 4
4x/4 = 16/4
x = 4
Therefore, the value of x that will make lime A parallel to line B is 4