Answer
y = ½x + 5
If y is the total amount Juanita makes for x inches of finished lanyard,
Base fee = y-intercept = 5
Cost per inch = Slope = 0.5 = ½
Explanation
To write the expression for this, we need to write the equation for the line representing the whole function
The slope and y-intercept form of the equation of a straight line is given as
y = mx + b
where
y = y-coordinate of a point on the line.
m = slope of the line.
x = x-coordinate of the point on the line whose y-coordinate is y.
b = y-intercept of the line.
From the gaph, we can easily see that
b = y-intercept = point where the line crosses the y-axis = 5
For the slope, for a straight line, the slope of the line can be obtained when the coordinates of two points on the line are known. If the coordinates are (x₁, y₁) and (x₂, y₂), the slope is given as
[tex]Slope=m=\frac{Change\text{ in y}}{Change\text{ in x}}=\frac{y_2-y_1}{x_2-x_1}[/tex]For this question,
(x₁, y₁) and (x₂, y₂) are (2, 6) and (6, 8)
[tex]\text{Slope = }\frac{8-6}{6-2}=\frac{2}{4}=\frac{1}{2}=0.5[/tex]Recall,
y = mx + b
m = slope = 0.5 = ½
b = y-intercept = 5
y = ½x + 5
If y is the total amount Juanita makes for x inches of finished lanyard,
Base fee = y-intercept = 5
Cost per inch = Slope = 0.5 = ½
Hope this Helps!!!