Answer:
30
Explanation:
If Line A is parallel to Line B, then 2x+50+5x-80 = 180. This is because 2x+50 is an alternate interior angle with the supplement of 5x-80, therefore the supplement of 5x-80 is also 2x+50. Supplementary angles add up to 180°.
Solve the Equation
2x + 50 + 5x - 80 = 180 --> Combine like terms
7x - 30 = 180 --> Add 30 to both sides
7x = 210 --> Divide both sides by 7
x = 30
Check the Solution
We can check our answer by plugging 30 in for x back into our original equation.
2(30) + 50 + 5(30) - 80 = 180
60 + 50 + 150 - 80 = 180
110 + 150 - 80 = 180
260 - 80 = 180
180 = 180
Therefore x = 30.