9514 1404 393
Answer:
- vertex: (7.5, 2.25)
- f(x) = -(x -7.5)² +2.25
Step-by-step explanation:
My favorite "technology" for problems like this is the Desmos graphing calculator app or web service. It easily displays the vertex (and/or zeros) of the function.
Of course, vertex form is ...
f(x) = a(x -h)² +k . . . . . . . . vertex (h, k), leading coefficient 'a'
The solution is found by reading the graph and putting the numbers in the formula. The leading coefficient is copied from the standard form equation.
- vertex: (7.5, 2.25)
- f(x) = -(x -7.5)² +2.25
so we know that 24% of the students buy their lunch at the cafeteria, and 190 students brownbag.
well, 100% - 24% = 76%, so the remainder of the students, the one that is not part of the 24% is 76%, and we know that's 190 of them.
since 190 is 76%, how much is the 24%?
![\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 190&76\\ x&24 \end{array}\implies \cfrac{190}{x}=\cfrac{76}{24}\implies 4560=76x \\\\\\ \cfrac{4560}{76}=x\implies 60=x \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{total amount of students}}{190+60\implies 250}](https://tex.z-dn.net/?f=%5Cbf%20%5Cbegin%7Barray%7D%7Bccll%7D%20amount%26%5C%25%5C%5C%20%5Ccline%7B1-2%7D%20190%2676%5C%5C%20x%2624%20%5Cend%7Barray%7D%5Cimplies%20%5Ccfrac%7B190%7D%7Bx%7D%3D%5Ccfrac%7B76%7D%7B24%7D%5Cimplies%204560%3D76x%20%5C%5C%5C%5C%5C%5C%20%5Ccfrac%7B4560%7D%7B76%7D%3Dx%5Cimplies%2060%3Dx%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Cstackrel%7B%5Ctextit%7Btotal%20amount%20of%20students%7D%7D%7B190%2B60%5Cimplies%20250%7D)
Answer:
3/4 gallon of purple paint left
Step-by-step explanation:
3/8 + 5/8 =8/8
he uses 2/8 so
8/8 - 2/8 = 6/8
3/4 (simplified)
12c=22
6c=11
c=1 5/6
20c=33
c= 1 13/20
5/6 is about .83
13/20 is .65
12 chocolate bars for $22 is about $1.83 each
20 chocolate bars for $33 is $1.65 each
The 20 chocolate bars for $33 dollars has a better unit rate and is a better buy.
