Step-by-step explanation:
dP/dt = -0.4P
Separate the variables and integrate.
dP/P = -0.4 dt
ln|P| = -0.4t + C
P = Ce^(-0.4t)
Use initial condition to find C.
2 = C^(0)
C = 2
P = 2e^(-0.4t)
dQ/dt = -1
Integrate.
Q = -t + C
Use initial condition to find C.
3 = 0 + C
C = 3
Q = -t + 3
Set the two equal.
2e(-0.4t) = -t + 3
Use a calculator to find t.
t = 2.156
The populations have the same size after 2.156 hours.
X= 1 Y=4
for every cup of flour there is four cookies
Go 3+4+2 to determine for 1 row and then multiply that by 64 so 576