Respuesta :

Answer:  x would have to equal 8

Step-by-step explanation: When a line intersects parallel lines it forms supplementary angles. The sum of two supplementary angles is 180°

We can use this information to set up an equation:

(6x -7 ) + (19x -13) = 180 . Combine like terms

25x -20 = 180  Add 20 to both sides.

25x = 200  Divide both sides by 25

x = 8

Check:

19(8) - 13  + 6(8) - 7 = 180

152 - 13 + 48 -7 = 180

139° + 41° = 180

The sum of the interior angles formed by the line is 180°, so lines a and b must be parallel.