Answer:
-3
Step-by-step explanation:

Answer:
a=3c+4b
Step-by-step explanation:
-8b + 2a = 6c
(-8b + 2a) + 8b = 6c + 8b
-8b + 2a + 8b = 6c + 8b
-8b + 8b + 2a = 6c + 8b
2a = 6c + 8b
2a/2 = 6c + 8b/2
a = (2x3)c +
x b)/2
a = 3c + 4b
It has been 1 hour and 20 minutes.
HOW I FOUND MY ANSWER:
7:10 to 8:10 = 1 hour
8:10 to 8:30 = 20 minutes
(1 hour + 20 minutes = 1 hr and 20 min.)
HOPE THIS HELPED
:)