The answer would be 29,112. That would be including the subtracted contribution.
Answer:
25 minutes
Step-by-step explanation:
25 mintes
Answer:
x = -7/3 or -5
Step-by-step explanation:
3x^2 + 22x = -35
3x^2 + 22x + 35 = 0
(3x + 7) (x + 5) = 0
so for 3x+7:
3x+7 = 0
3x = -7
x = -7/3
So for x + 5:
x + 5 = 0
x = -5
Answer:
Credit remaining after 21 minutes = $30.4
Step-by-step explanation:
Credit remaining on a phone card is a linear function of the total calling time.
When graphed, let the linear function representing the line is,
y = mx + b
Where 'm' = slope of the line
b = y-intercept
From the graph,
Slope of the line = -0.12
y = -0.12x + b
If this line passes through a point (33, 28.96),
28.96 = -0.12(33) + b
b = 28.96 + 3.96
b = 32.92
Therefore, the linear function is,
f(x) = -0.12x + 32.92
where x = calling time
Credit left in the card after 21 minutes,
f(21) = -0.12(21) + 32.92
= -2.52 + 32.92
= $30.4
