Answer :
- 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
Answer:
Part (a)
Given equation:
[tex]y = - 1.25x + 25[/tex]
- [tex]x[/tex] = number of donuts Brianna buys
- [tex]y[/tex] = total amount of money in Brianna's pocket (in dollars)
- [tex]-1.25[/tex] = For every donut Brianna buys, the money in her pocket decreases by $1.25 ⇒ each donut costs $.125
- [tex]25[/tex] = 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 [tex]y = 0[/tex] into the equation and solve for [tex]x[/tex]:
[tex]\implies 0=-1.25x+25[/tex]
[tex]\implies 1.25x=25[/tex]
[tex]\implies x=\dfrac{25}{1.25}[/tex]
[tex]\implies x=20[/tex]
Therefore, the greatest number of donuts Brianna can buy is 20 donuts.