Holy @$#% THAT LOOKS HARD! Sorry, I can't help I don't know that math yet.
if you want to be sure :/
let's say the breakfast price was "x", so that's the 100%, and we know she gave 20% of that and that is 1.80.
so, 1.80 is 20%, and "x" is the 100%, what is "x"?
![\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 1.80&20\\ x&100 \end{array}\implies \cfrac{1.80}{x}=\cfrac{20}{100}\implies \cfrac{1.8}{x}=\cfrac{1}{5} \\\\\\ 9.0=x\implies 9=x](https://tex.z-dn.net/?f=%5Cbf%20%5Cbegin%7Barray%7D%7Bccll%7D%20amount%26%5C%25%5C%5C%20%5Ccline%7B1-2%7D%201.80%2620%5C%5C%20x%26100%20%5Cend%7Barray%7D%5Cimplies%20%5Ccfrac%7B1.80%7D%7Bx%7D%3D%5Ccfrac%7B20%7D%7B100%7D%5Cimplies%20%5Ccfrac%7B1.8%7D%7Bx%7D%3D%5Ccfrac%7B1%7D%7B5%7D%20%5C%5C%5C%5C%5C%5C%209.0%3Dx%5Cimplies%209%3Dx)
Answer:
D
Step-by-step explanation:
convert into vertex form
x^2-4x+4 = (x-2)^2 +0
vertex: (2, 0)
Graph D has vertex (2, 0)