Answer:
C.
Step-by-step explanation:
Each of the graphs is clearly a straight line, apart from graph C. Graph C is a parabola.
Answer:
y = -(5/2)x -2
Explanation:
The general formula for a straight line is y – mx + b.
The image below shows the graph of the line.
Step 1. <em>Calculate the slope</em>.
Slope = m = Δy/Δx = (y₂-y₁)/(x₂-x₁)
x₁ = 0; y₁ = -2
x₂ = -2; y₂ = 3 Calculate m
m = [3-(-2)]/(-2-0)
m = (3+2)/(-2)
m = 5/(-2)
m = -5/2
Step 2. <em>Calculate the y-intercept
</em>
When x = 0, y = 2.
The y-intercept (b) is at y = -2
Step 3. <em>Write the equation </em>for the graph
y = mx + b
y = -(5/2)x - 2
For this problem, you know that the first walker will arrive 2 hours before the second, and increases his speed by 2 times the second walker. You also know there is a distance of 24 km. So up until some time x, the two walkers have to be going the same speed. If the first walker increases speed by two times the speed per hour, and arrives two hours earlier, then his initial speed will be 20 km/h, because after 2 hours, he will have an increase of 4 km/hr, and the second will have an increase of 2 km/h, thereby making the first arrive 2 hours earlier, if that makes sense.
The problem statement suggests you should convert dimensions to inches to work this problem.
.. 2.75 ft = 33 in
.. 1.5 ft = 18 in
The empty height is
.. 0.6*7 in = 4.2 in
so the empty volume is
.. V = (33 in)*(18 in)*(4.2 in) = 2494.8 in³
Multiplying this by the conversion factor to gallons gives
.. V = (2494.8 in)³ × (1 gal)/(231 in³) = 10.8 gal
It will take 10.8 gallons of gas to fill the tank.
