Answer:
f(x) = (8/3)x(x - 1).
Step-by-step explanation:
The vertex form of the function is
y = a(x - 1/2)^2 - 2/3 where a is some constant.
Now the roots are 0 and 1 so
For x = 0
0 = a(-1/2)^2 - 2/3
1/4 a = 2/3
a = 2/3 / 1/4 = 8/3.
So the function is
f(x) = (8/3)(x - 1/2)^2 - 2/3.
3 f(x) = 8(x - 1/2)^2 - 2
= 8(x^2 - x + 1/4) - 2
= 8x^2 - 8x + 2 - 2
3 f(x) = 8x(x - 1)
f(x) = (8/3)x(x - 1).
Answer: a burger is $5.25, fries are $1.50
b = burger, f = fries
3b + 3f = 20.25
5b + 8f = 38.25
First, solve for b in terms of f
3b = 20.25 - 3f
b = 6.75 -f
Then substitute that for b in the other equation to solve and get a numerical value for f.
5(6.75 -f) + 8f = 38.25
33.75 -5f +8f = 38.25
33.75 + 3f = 38.25
3f = 4.5
f = 1.5
Now substitute that in to get a numerical value for b
b = 6.75 - 1.5
b = 5.25
Checking the math:
3b + 3f = 20.25
3(5.25) + 3(1.5) = 15.75 + 4.5 = 20.25
He has 11 quarters, 9 dimes, and 55 nickels.
11x.25=2.75
9x.1=.9
55x.05=2.75
2.75+2.75+.9=6.4