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
6h-4
1. Substitute 5 for h
6(5)-4
30-4 =26
Answer:
$0.57
Step-by-step explanation:
7 pound = 4 $
1 pound =4/7 $
=0.57$
I'm not 100% sur what it is asking but I think the expression would be
15 min. * 10 = min. till the tank is full
