Given :
The bread machine you are interested in costs $168 with tax.
The ingredients to make one loaf of bread cost $1.50.
A) What is the cost of ingredients for one loaf of bread?
It will be the given value = $1.5
B) What is your start up cost? (cost of machine)
The cost of the machine = $168
C) Write a linear equation, y = mx + b, for the total cost of x loaves of bread.
Let the number of loaves of bread = x
And the total cost = y
so, the equation will be :

D) Graph the equation. Be sure to locate at least 3 points.
To locate the the points , substitute with 3 value of x and find the corresponding values of y
The graph of the equation will be as shown in the following picture
The 3 points are :
when x = 6 , y = 6 *1.5 + 168 = 177
When x = 10 , y = 10 * 1.5 + 168 = 183
When x = 20 , y = 20 * 1.5 + 168 = 198
So, the points are ( 6,177 ) , ( 10 , 183 ) and ( 20 , 198 ) which are in red colors on the graph
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For the second case :
A loaf of bread of similar quality in the store costs $2.50.
And there is no other cost
so, the equation will be :

And the graph of the equation will be :
We will graph the two lines on the same graph, it will be as shown in the following figure:
Estimate the ordered pair where the two lines cross:
the red line represents the equation : y = 1.5x + 168
The blue line represents the equation : y = 2.5 x
As shown the order pair where the two lines cross is the point ( 168 , 420 )
So,
It would take _168_ loaves at a cost of $_420_ for the bread maker and store bought bread to cost the same.