Answer:
20
Step-by-step explanation:
Answer:
I am guessing about 150 - 200 students did not buy a yearbook.
Step-by-step explanation:
First let's assume that there are 1,000 or so students in the school. 856 would be a little over 4/5 of 1,000 just as 8 would be 4/5 of 10.
F ` ( x ) = ( x² )` · e^(5x) + x² · ( e^(5x) )` =
= 2 x · e^(5x) + 5 e^(5x) · x² =
= x e^(5x) ( 2 + 5 x )
f `` ( x ) = ( 2 x e^(5x) + 5 x² e^(5x) ) ` =
= ( 2 x ) ˙e^(5x) + 2 x ( e^(5x) )` + ( 5 x² ) ` · e^(5x) + ( e^(5x)) ` · 5 x² =
= 2 · e^(5x) + 10 x · e^(5x) + 10 x · e^(5x) + 25 x² · e^(5x) =
= e^(5x) · ( 2 + 20 x + 25 x² )
So the actual meal was at most 130 dollars they paid minus the 20 dolars tip: 130-20=110 dollars.
it was 5 people: Dolores+5 friends, who presumably all paid the same (buffet).
then we have to divide the 110 among the 5 people: it's 110/5=22
so each of them paid at most 22 dollars:
x (the amount they paid)≤22
