Answer:
x = 25
Step-by-step explanation:
x = # of hrs he worked at his weekday job
w = # of hours he worked at his weekend job
25+ x = 40y = 40 - 25 = 15.
Therefore, Mia worked for 25 hours at his weekday job and 15 hours at his weekend job.
w + x = 40
20x + 18w = 770
18(x + w = 40) = 18x + 18w = 720
(20x + 18w = 770) - (18x + 18w = 720)
2x=50
x=25