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The equation below represents the amount of money left in Brianna’s pocket after buying donuts for her friends:
y = - 1.25x + 25
a)Explain what each value in the equation represents.
b)What is the greatest number of donuts Brianna can buy

User Sarika
by
8.6k points

2 Answers

10 votes
  • y=-1.25x+25

Here rate of change is -1.25 (-ve) hence

  • x represents no of donuts
  • y represents price left

#b

The greatest no of donuts

  • -1.25x+25=0
  • -1.25x=-25
  • x=20donuts
User Jeevium
by
7.7k points
11 votes

Answer:

Part (a)

Given equation:


y = - 1.25x + 25


  • x = number of donuts Brianna buys

  • y = total amount of money in Brianna's pocket (in dollars)

  • -1.25 = For every donut Brianna buys, the money in her pocket decreases by $1.25 ⇒ each donut costs $.125

  • 25 = Total amount of money Brianna has before she buys any donuts (in dollars) ⇒ $25.00

Part (b)

The greatest number of donuts Brianna can buy is when the money she has is reduced to zero dollars. Therefore, substitute
y = 0 into the equation and solve for
x:


\implies 0=-1.25x+25


\implies 1.25x=25


\implies x=(25)/(1.25)


\implies x=20

Therefore, the greatest number of donuts Brianna can buy is 20 donuts.

User Mike Anderson
by
8.3k points
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