Answer:
1. (a) y = 0.50 x+ 15
1. (b) The graph is a straight line
1. (c) Slope = 0.50; y-intercept = (0, 15)
Step-by-step explanation:
1. (a) The equation
There are two variables: the total rental cost (y) and the distance travelled (x).
The total rental cost depends on the distance travelled.
The initial cost is the $15 flat fee.
The rate at which the cost increases is $0.50/mi.
The equation for the relationship iss then
y = 0.50x + 15
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1. (b) The graph
The graph of the equation is a straight line on a coordinate plane (see below).
It shows that the cost starts at $15 and increases at a constant rate.
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1. (c) The slope and y-intercept
The y-intercept is the point at which the graph crosses the y-axis: (0, 15).
The equation for the slope is
Slope = (y₂ - y₁)/(x₂ - x₁)
Let’s pick the points
x₁ = 10, y₁ = 20
x₂ = 90, y₂ = 60 Calculate the slope
Slope = (60 – 20)/(90 – 10)
Slope = 40/80
Slope = 0.50
The y-intercept represents the $15 flat fee and the slope represents the rate of $0.50/mi.
