This is how I'd set it up:
405/20 = 243/x
this means the mpg (miles / gallons) for 1 situation is the same as the mpg for the other situation (because the rate is the same)
then just cross multiply and solve:
405x=243*20 or 405x=4860 or x = 12
he would need 12 gallons of gas for 243 miles
1, 3/3, 420/420 why such a wierd qustion
Answer: - 2 and 6
Step-by-step explanation:
Answer:
13
Step-by-step explanation:
count the big ducks first
then go back and count the smaller ones
Answer:
Step-by-step explanation:
Not sure what form you need this in, but it really doesn't matter, as you'll see in the final equation. I used the vertex form and solved for a:

We are given the vertex (h, k) as the origin (0, 0), and we have a point that the graph goes through as (4, -64). That's our x and y. Plugging in what we have:
gives us
-64 = 16a and
a = -4. That means that the quadratic equation is
which is both vertex form and standard form here, no difference.