For y = -x², the vertex = (0,0)
Dan's age is x.
Jack is three years older than Dan, so his age is x+3.
Harold is twice as old as Jack, so his age is 2(x+3).
Harold's age is five times Dan's age.

Jack is 5 years old.
Sub y in the second equation by y in the first equation:
We get 4x+3(-3x+3)=-1
4x-9x+9=-1
-5x=-10
x=2
Sub in the first equation
y=-3(2)+3
y=-3
Answer: um last time i heard fsa my teacher said its for florida standards assessments
Step-by-step explanation: