Answer:
Following are the solution to the given question:
Step-by-step explanation:
Please find the attached file for the solution:
20% of flights accounted for nearly 70 to 80% of delayed minutes.
The vertex is (-2,-8)
So the y-value would be -8
3/4-4z+5/4z-1/2+1/2z
(simplify fractions by taking away)3/4-1/2=1/4
(simplify again but only fraction with a denominator of z)5/4z+1/2z=7/4z
so its 1/4+7/4z-4z
OR
I don't know if you're supposed to change by taking away 4z which is the same as 1/4z.
if so then
7/4z(previous calculation but you can use the beggining fractions if you want just add all 3 fractions with z as a denominator)-1/4z=6/4z
so its 1/4+6/4z
I don't know the others sorry