David's age is four times alisa’s age. in eight years, david will be twice as old as alisa. how old is each now?

Alissa's current age = 4

David's current age = 16

Step-by-step explanation:

if say Alissa is x years old then David is 4x years old

in 8 years Alissa will be x+8, and David 4x+8 and that's twice as Alissa's age therefore:

2×(x+8)=4x+8

2x+16 = 4x+8

16-8=4x-2x

8=2x

x=4

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50

f is the midpoint of