We are trying to find miles/hour, which shows that we are going to be dividing the total number of miles by the total number of hours. Thus, in this case, the miles/hour rate will be:

He drove 40 miles in one hour.
Answer:
y = 3x -13
Step-by-step explanation:
y = 3x + 7
-1 = 3(4) + b
-1 = 12 + b
-13 = b
y = 3x -13
Multiply both sides by 10.
2b=990
divide both sides by 2
b= 495
Answer:
$5599.20
Step-by-step explanation:
The quarterly interest rate for the first two years was ...
7%/4 = 0.0175
So, the multiplier each quarter for those 8 quarters was 1+0.0175 = 1.0175. At the end of the first 8 quarters, the account value had been multiplied by ...
1.0175^8
For the next 8 quarters, the quarterly interest rate was 10%/4 = 0.025. So at the end of those 8 quarters, the balance had been multiplied by ...
1.025^8
Then the balance at the end of 4 years was ...
$4000(1.0175^8)(1.025^8) ≈ $5599.20
The balance was $5599.20.