Answer:

Step-by-step explanation:
Vertex form of a quadratic is given by:

Where (h, k) is the vertex and <em>a</em> is the leading coefficient.
We are given that the vertex is (3, 1). Hence, <em>h</em> = 3 and <em>k </em>= 1. By substitution:

We are also given a point (2, -6). This means that when <em>x </em>= 2, <em>f(x)</em> = -6. Hence:

Solve for <em>a</em>. Subtract:

Simplify:

Therefore:

Hence, our quadratic is:

20 less than 1000 is the same thing as 1000 minus 20.
1000 minus 20 is 980.
20 less than 1000 is 980.
Answer:
Every 18 miles he uses 3 gallons
divide this:
18 ÷ 3 = 6 miles per gallon
30 miles = 30 ÷ 6 = 5 gallons
7 gallons = 7 x 6 = 42 miles
48 miles = 48 ÷ 6 = 8 gallons
10 gallons = 10 x 6 = 60 miles
Hope this helps :D