The part D is the correct one...
A quadratic function whose vertex is the same as the y-intercept has the equation
y=x^2+k (where k is the y-intercept, with vertex (0,k))
Since the vertex coincides with the y-intercept, the axis of symmetry is x=0.
Answer:

Step-by-step explanation:
Given

Required
Determine the amount of sweet Ivy gets when Dennis = 42
We have:
and

Substitute 42 for Dennis in 

Convert to fraction

Cross Multiply:

Divide through by 7




Answer:
3 gallons
Step-by-step explanation:
If two gallons of paint covers 800 square feet, 'x' gallons of paints will cover 1200square feet room where x is the number of gallons needed to paint the 1200 square feet room.
Mathematically,
2 gallons = 800sq.ft
x gallons = 1,200sq.ft
x × 800 = 2 × 1200
x = 2 × 1200/800
x = 3 gallons
Therefore Leah will need 3gallons of paint for 1200sq.ft room