Answer:
slope = 5/3
y - intercept is 0.
y = 5/3x is the required equation.
3.33 gallons of gas left.
4.08 hours
Explanation:
Given: A truck has 20 gallon of gas.
Every three hours, the car uses 5 gallons of gas.
1 hour = 5/3
That is the slope = 5/3
x(jpours) y (gallons)
3 5
6 10
9 15
12 20
Now let's form the equation.
Let's take two coordinates (3, 5) and (6, 10)
Here x1 = 3, y1 = 5, x2 = 6 and y2 = 10
Slope(m) = (y2 - y1) /(x2 - x1)
m = (10 - 5) / (6 - 3) = 5/3.
Now let's find the y-intercept b
y = mx + b
5 = 5/3 (3) + b
5 = 5 + b
b = 5 - 5
b = 0
Therefore, y - intercept is 0.
y = 5/3x is the required equation.
Now we have to find how much gas left 10 hours
Now plug in x = 10, in the equation.
y = 5/3 (10)
y = 50/3
y = 16.67
It uses 16.67 gallons for 10 hours.
Number of gallons left after 10 hours = 20 -16.67 = 3.33 gallons of gas left.
Now we have to find how long will it take for the truck to have 6.8 gallons.
Plug in y = 6.8 in the equation, we get
6.8 = 5/3 x
x = 6.8 *3/5
x = 20.4/5
x = 4.08 hours
Thank you.