Problem 4
9x + 27 y = 45
The slope of the equation is..

Slope = -1/3

Step-by-step explanation:

9x + 27y = 45

Let's rearrange

Following the equation of a line

y = mx + c

y - intercept point y

x - intercept point x

m - slope of the line

c - intercept of the line

9x + 27y = 45

27y = 45 - 9x

27y = -9x + 45

Divide both sides by 27 , to make the y the subject of the formula

27y/27 = ( -9x + 45)/27

y = ( -9x + 45)/27

y = mx + c

We have to separate, so as to get the slope and also the intercept

y = ( -9x + 45)/27

y = -9x/27 + 45/27

We can simply further

y = -x/3 + 5/3

Therefore, the slope of the equation is -1/3

The intercept is 5/3

e^-kt = n/n0 = 0.79  

-kt = ln 0.79  

t = - ln 0.79/0.0001  

= 2357 years

step-by-step explanation: