Write the equation of the parabola with a focus (-2,4) and directrix y = 0.

y=0 means sideways from the usual orientation. The definition of a parabola is equal distances of (x,y) to the focus and the directrix.  We equate squared distance:

(x + 2)² + (y - 4)² = (y - 0)²

x² + 4x + 4 + y² - 8y + 16 = y²

x² + 4x + 20 = 8y

We could divide by 8 to get y= something but let's just skip the fractions and answer

8y = x² + 4x + 20

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: