Question

Find the value of x that will make A parallel to B
2x + 50
5x - 80
x = ?

Answer 1

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.