Let m = minutes of commercial
30/90 = 8/m
Solve for m.
90(8) = 30m
720 = 30m
720/30 = m
24 = m
Answer:
-89
Step-by-step explanation:
The first term of the sequence is a1 = -12.
The common difference between terms is ...
d = -13 -(-12) = -1
The generic term is given by ...
an = a1 +d(n -1)
Then the 78th term is ...
a78 = -12 +(-1)(78 -1) = -12 -77
a78 = -89
She regrouped the numbers instead of multiplying like 8b(2b-r) -4r(2b-r).