Direct variation is of the form y=kx, where k is the constant of variation. It is "direct" because as x increases/decreases so does y in the same magnitude.
y=kx, In this case the dependent variable y, is miles and the independent variable x, is gallons. We are told that the car gets 28mi/gal so
y=28x
Since the ratio is 4:9 your trying to find the sum. What I mean is that if it's 4 to 9, whats 20+9? =29. Do the same for 4. 20+4= 24. Now you find the difference in order to find how much does Byron have compared to Jonathan. So 29-24= 5
Below is the formula for the circumference of a circle
C = 2πr
This question gives us the diameter. To find the radius (r) you would divide the diameter by two like so...
16.4/ 2 = 8.2
Plug what you know into the formula and solve...
π = 3.14
r = 8.2
C = 2(3.14)(8.2)
C = 6.28(8.2)
C = 51.496
In the question it asks to round to the nearest tenth like so...
51.5
Hope this helped!
~Just a girl in love with Shawn Mendes
