Question 1195743
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Part A


Jacob has $45.
Muffins costs $0.75 each.
Divide the values to get 45/(0.75) = 60


Answer: <font color=red>60 muffins maximum</font>


Note: this of course means Jacob cannot buy any doughnuts.


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Part B


Follow the same idea as the previous part.
This time we divide 45 over 0.25
45/(0.25) = 180


Answer: <font color=red>180 doughnuts maximum</font>


Jacob cannot buy any muffins in this scenario.


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Part C


x = number of muffins
y = number of doughnuts
These are nonnegative whole numbers.


Muffins are $0.75 each. 
Buying x of them costs a subtotal of 0.75x dollars.


Doughnuts are $0.25 each.
Buying y of them costs a subtotal of 0.25y dollars.


The grand total is 0.75x+0.25y dollars
Assuming Jacob spends all of the $45, then we set the grand total algebraic expression equal to the 45.


Answer:  <font color=red>0.75x+0.25y = 45</font>


Side note: The equation in red is equivalent to y = -3x+180
I'll stick with the previous version because it shows the 0.75 and 0.25 to help show how each piece contributes to the total. 


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Part D


x = number of muffins
y = number of doughnuts


From part A, we found that Jacob can buy 60 muffins and 0 doughnuts. This leads to one ordered pair point of (x,y) = (60,0)


In part B, we found that he can buy 0 muffins and 180 doughnuts. This produces the point (0, 180)


Plot the two points (60,0) and (0,180) and draw a straight line through them. I'll let you check that they work with the equation 0.75x+0.25y = 45 found in part C.


To find other points, follow these steps:
1) Pick any whole number between 1 and 59.
2) Replace x with that value.
3) Solve for y.


At minimum, you only need 2 points to form any straight line.


Answer:
<img src = "https://i.imgur.com/QFbI0ZU.png">
I used GeoGebra to make the graph.
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