Answer:
x = 20
Step-by-step explanation:
By the alternate interior angles theorem, angle 2 and angle 3 are congruent.
∠2 ≅ ∠3
3x- 10 = x + 30 substitute the values
3x = x + 40 add 10 to both sides
2x = 40 subtract x from both sides
x = 20 divide both sides by 2
