Answer:
90 days.
Step-by-step explanation:
dy/dt = - 0.0032y
dy = -0.0032y dt
dy/y = -0.0032 dt
Integrating:
ln y = -0.0032t + c where c is some constant
y = e^(-0032t) + e^c
y = A e^(-0032t) where A is a constant.
At time 0 we can let y = 1 so in that case A = 1
When there is 0.75 of y left:
0.75 = e^-0032t
ln 0,75 = -0032 t
t = ln 0.75 / -0032
t = 90.
Answer:
x= -5
Step-by-step explanation:
just use a calculator
Answer:
y = -5
Step-by-step explanation:
-3x +9y = -57
Let x = 4
-3*4 +9y = -57
-12 +9y = -57
Add 12 to each side
-12+12 +9y = -57+12
9y = -45
Divide each side by 9
9y/9 = -45/9
y = -5
Answer:
A
Step-by-step explanation:
y-1=3-1/-2-5 (x-5)
2x+7y=17