Part A: Yes, the data represent a function. The definition of a function is a relation in which no value of x will have two different values of y.
(Every time you plug in 3 as x, you will always get 4 as y; it's ok if you plug in 3 and 5 as x and get the same y, you just can't get two different y's for one x; sorry, it is pretty confusing). None of the numbers in the table repeat, so we can safely say that the relation is a function.
Part B: All we have to do is plug in 11 for x in the function given to find the answer:

In the table, y = 8 when x = 11, but in the function given, y = 34 when x = 11, so the function given is greater.
Part C: To find the answer to C, just plug in 99 for f(x), as it tells you to do:
The constant variation for the relationship being shown is 4
Step 1: Simplify both sides of the equation.
Step 2: Subtract 6x from both sides.
- 65x²+390x+585−6x=6x−6x
- 65x²+384x+585=0
For this equation: a=65, b=384, c=585
Step 3: Use quadratic formula with a=65, b=384, c=585
- x=−b±√b2−4ac/2a
- x=−(384)±√(384)2−4(65)(585)/
- 2(65)
- x=−384±√−4644/130
Therefore, There are no real solutions.
All sides of an equilateral triangle are equal, so all three sides are 9 cm.
To find h, use the pythagorean theorem. This requires use of only one right triangle, where we use b as our h.
a^2+b^2=c^2
(4.5)^2+b^2=(9)^2
(20.25)+b^2=(81)
b^2=(81/20.25) or 4
square root both sides
b=2