Answer:15Step-by-step explanation:So angle 2 and angle 4 have a relationship that is called same-side interior or consecutive interior angles. The name there depends what class you are in but they mean the same thing.If you have the transversal goes through parallel lines, then same-side interior angles will add up to 180 degrees.So you are trying to solve the following equation for x:angle2+angle4=1802x+10+4x+80=180Combine like terms:6x+90=180Subtract 90 on both sides:6x =90Divide both sides by 6: x =90/6Simplify: x =1515 is x so that the lines are parallel