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
Answer:
the first one first the second second and the last last
Step-by-step explanation:
2 1/5 + 22/5 = 4 2/5
9 2/5 + (-5 3/5)= 4 1/5
-8 2/5+9 1/5=1/15
You can do this by first finding the y intercept which is the point where x = 0
-3(0) + y = 2
so y intercept is the point (0,2)
Now find the x intercept by putting y = 0
-3x = 2
x = -2/3
So we have 2 points (-2/3, 0) and (0,2) Draw a line through these 2 points and you have the required graph.
If I pick 10, then 2(10)+13=33
If I pick 15, then 2(15)+13=43
If I pick 12, then 2(12)+13=37