The function is a parabola which opens downwards.
-x^2 - 2x + 15
-(x^2 + 2x) + 15
= -[(x + 1)^2 - 1 ]+ 15
= -(x + 1)^2 + 16
The domain is all real numbers and the range is {y|y <= 16}
Its the second choice.
I would have guessed point S is (3,0).
Let, the cost of 1 piece of fudge = x
Cost of a gum = y
System of equations: 5x + 3y = 5.70
2x + 10y = 3.60
Multiply 1st equation by 2, and second by 5,
New equations: 10x + 6y = 11.40
10x + 50y = 18
Now, subtract 1st from 2nd,
44y = 6.60
y = 6.60 / 44
y = 0.15
Substitute it in second equation,
2x + 10(0.15) = 3.60
2x = 3.60 - 1.5
x = 2.10 / 2
x = 1.05
In short, Cost of a Fudge = $1.05 & Cost of a gum = $0.15
Hope this helps!
miren pongan enpeño en matematica
