The calculation of the integral will give us the answer.
Amount = Int (2000e^(-0,2t))dt
With t = 0 to t = 10
A = 2000.In(e^(-0,2t))dt
Making U = -0,2t
U = -0,2t
dU/dt = d(-0,2t)/dt
dU/dt = -0,2
dU = -0,2dt
dt = dU/-0,2
_______________
Then,
A = 2000.Int (e^U).dU/-0,2
A = -10.000.Int(e^U)dU
A = -10.000.e^U
A = -10.000.e^(-0,2t) | (0,10)
A = -10.000.(e^(-2)) - [ -10.000.e^(0)]
A = -10.000.e^(-2) + 10.000
A ~ 8,646 Gallons
Subtract 5 from both sides.

Subtract 8n from both sides.

Divide both sides by -9 to solve for n.

The value of n is
-4/9.
This line y = 4/5 x - 3 has slope = 4/5
Perpendicular lines, slope is opposite and reciprocal so slope of a line that is perpendicular to the line y = 4/5 x - 3 is -5/4
Answer
- 5/4
Just remove the parenthesis since you are adding them and combine like terms
x+5+2x+3
3x+8