Answer: y = 8*x + 5
Explanation:
Here we have the points (1, 13), (2, 21), (3, 29), (4, 37)
You can see that the x-component always increases by one unit, while the y-component always increases by 8 units.
Then we can conclude that this is a linear relationship.
A linear relationship can be written as:
y = a*x + b
where a is the slope and b is the y-axis intercept.
For a line that passes through the points (x1, y1) and (x2, y2), the slope can be written as:
a = (y2 - y1)/(x2 - x1).
Here we can use the fact that our line passes through the points (1, 13) and (2, 21)
Then the slope of our line is:
a = (21 - 13)/(2 - 1) = 8
Then:
y = 8*x + b
To find the value of b, we can use again the fact that our line passes through the point (1, 13)
This means that when x = 1, the value of y is 13, if we replace that in the equation we get:
13 = 8*1 + b
13 = 8 + b
13 - 8 = b
5 = b
Then:
y = 8*x + 5
This means the amount charged for x hours, is:
y = 8*x + 5