Answer:
y = 68
Step-by-step explanation:
For the lines to be parallel, then
78 and 2y - 34 are same- side exterior angles and supplementary, thus
2y - 34 + 78 = 180
2y + 44 = 180 ( subtract 44 from both sides )
2y = 136 ( divide both sides by 2 )
y = 68
