3375/225=15
13500/15=900 books
The answer is D
y -3x =1
add 3x to each side
y = 3x+1
The coefficient for x is 3 and the constant is 1
If the endpoints of a diameter are (6,3) and (2,1) the midpoint is the center of the circle so:
(x,y)=((6+2)/2, (3+1)/2)=(4,2)
Now we need to find the radius....the diameter is:
d^2=(6-2)^2+(3-1)^2
d^2=16+4
d^2=20 since d=2r, r=d/2, and r^2=d^2/4 so
r^2=5
The standard form of the circle is (x-h)^2+(y-k)^2=r^2 and we know:
(h,k)=(4,2) from earlier so:
(x-4)^2+(y-2)^2=5
3y(2 - y) + 8y
6y - 3y^2 + 8y
-3y^2 + 14 y
