The longest chord on the circle is the diameter, and the center of the circle is the midpoint of the diameter.
Use the midpoint formula to find the center
((x1 +x2)/2 , (y1+y2)/2).. Just substitute them for the solution
the x-coordinates are the same, so you can just subtract the y-coordinates to find the radius.
10.5 - 8 = 2.5
The equation of the circle is (x - h)² + (y - k)² = r² where r is the radius and (h, k) is the center.
(x - 4)² + (y - 8)² = 6.25
To see what are the factors use, we write each of the numbers, as product of prime factors:

As we can see, the 4 factors used to produce the numbers in the list are {2, 3, 5, 7}
Answer: {2, 3, 5, 7}
Does that mean solve for y? If so, here it is:
5x + 2y = 11.
Move the x term by subtracting.
2y = -5x + 11
Divide by 2.
y = -5/2x + 11/2
The answer is 16, you substitute the value of the variable into the equation and simplify
There are 16 cups in the gallon