How many hours will it take a culture of bacteria to increase from 20 to 2000 if the growth rate per hour is 85%

Approximately

7.5

hours

Step-by-step explanation:

Explanation:

We are trying to determine the value of

h

in the compound growth formula

XXX

20

×

(

1

+

0.85

)

h

=

2000

or, simplified:

XXX

1.85

h

=

100

Taking the

log

1.85

of both sides:

XXX

log

1.85

100

With the aid of my trusty spreadsheet:

XXX

h

≈

7.48582192

it is x=-4

step-by-step explanation:

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116