Answer:
The constant in the expression is 12
Step-by-step explanation:
The constant of the expression is the value that is independent of the number of minutes Janelle uses. The expression can be written as :
f(m)=0.05m +12
Example if m is 1 or 2
f(1) = 0.05(1) +12 = 12.05
f(2= = 0.05*2 +12 =0.1 +12 = 12.1
The value 12 is the minimum price of the bill indepent of the consumption of minutes of Janelle. She will always be charged this value.
4 is equal to 2*2 (double the 2 is 4)
we know that
we have
substitute the value of 
in the expression above
therefore
<u>the answer is</u>
Answer:
x intercept: (3, 0), (7, 0)
y-intercept: (0, -21)
vertex : (5,4)
the graph points down
Step-by-step explanation:
f(x) = - (x - 3)(x - 7)
f(x) = - (x^2 - 7x - 3x + 21)
f(x) = - (x^2 - 10x + 21)
f(x) = -x^2 + 10x - 21
x-intercept when f(x) = 0 so
x - 3 = 0; x = 3
x - 7 = 0; x = 7
x intercept: (3, 0), (7, 0)
y-intercept when x = 0 so y = -21
y-intercept: (0, -21)
vertex:
x = -b/2a
x = -10/ 2(-1)
x = 5
plug in x = 5 into the equation to find y
y = -(5)^2 + 10(5) - 21
y = -25 + 50 - 21
y = 4
so vertex : (5,4)
Since a = - 1<0, the graph is going downward and has maximum
