Answer:
Answer z = 55
Step-by-step explanation:
Remark
I think you have to assume that the horizontal line is a straight line. If that is so, the other line, the one that looks like it is going up and to the left, cuts that horizontal line in such a way that the angles are supplementary. Supplementary angles are angles that add up to 180 degrees.
Equation
2z - 10 + 80 = 180 Combine the like terms on the left.
Solution
2z + 70 = 180 Subtract 70 from both sides.
2z + 70 - 70 = 180 - 70 Combine
2z = 110 Divide by 2
2z/2 = 110/2 Do the division
z = 55 Answer
