Answer:
Ms. Thomas was driving at constant rate of 52 miles/hour.
Step-by-step explanation:
Given:
Total time to travel (t) = 45 minutes
Distance drove (d) = 39 miles
we need to find the constant rate in miles per hour at which she was driving.
Solution:
Now we know that;
We need to find constant rate at miles per hour;
But time is given in minutes.
So we will convert minutes into hour by dividing by 60 we get;
time 
Now we know that;
Distance is equal to rate times time.
framing in equation form we get;
distance 
Or
rate 
Hence Ms. Thomas was driving at constant rate of 52 miles/hour.
You would first make the fractions improper (making the numerator bigger then the denominator) in order to do that times the denominator with the whole number and add the numerator.
Ex) 3*8 = 24 + 5 = 29/8
Then you would add both of the improper fractions
we know that
the perimeter of the rectangle is equal to

where
P is the perimeter of the rectangle
W is the width of the rectangle
L s the length of the rectangle
In this problem

Substitute the values in the formula above


therefore
the answer is
the length of the longer side of the rectangle is equal to 
Answer: He bought 7 pens.
Step-by-step explanation:
21/3 = 7
The LCM of these 2 is 36, 18 goes into it only twice and 12 goes into it 3 times