I’m not sure about this one folks plz help:D

35 is the answer
Explanation, the sum of interrior angme is 180degree
x+(3x+40)= 180
or, 4x= 180-40
or, x= 140÷ 4
or x = 35
Answer:
B
Step-by-step explanation:
For the 2 lines to be parallel, then the 2 angles are same- side interior angles and are supplementary, thus
x + 3x + 40 = 180 , that is
4x + 40 = 180 ( subtract 40 from both sides )
4x = 140 ( divide both sides by 4 )
x = 35 → B