c. the number of persons allegric to penicillin
Answer:
13525
Step-by-step explanation:
Given the equation :
y=25,450(0.81)^t
where (t) is the number of years since the truck was new ;
The value of y when t = 3 ;
Replace, t with 3 in the equation. And simplify
y=25,450(0.81)^3
Y = 25450 * 0.531441
y = 13525.17345
Worth after 3 years = 13525
Answer:
x=1 , y = -1
Step-by-step explanation:
-2.4x-3.6y = 1.2
2.4x+1.2y = 1.2
Add the equations together
-2.4x-3.6y = 1.2
2.4x+1.2y = 1.2
---------------------------
-2.4 y = 2.4
Divide by -2.4
y = -1
Now find x
2.4x +1.2y = 1.2
2.4x +1.2(-1) = 1.2
2.4x -1.2 = 1.2
Add 1.2 to each side
2.4x -1.2+1.2 = 1.2+1.2
2.4x = 2.4
Divide by 2.4
x = 1