Harriet is cultivating a strain of bacteria in a petri dish, she has 10^3 bacteria in the dish. The bacteria divided every two hours such that the number of bacteria has doubled by the end of every second hour. How many bacteria will Harriet have in the dish at the end of 6 hours?

4000

Step-by-step explanation:

A=P(2)^(t/d)

A=future amount

P=starting amount

t=time elapsed

h=doubling time

given

P=10^3

t=6

d=2

A=10^3(2)^(6/2)

A=10^3(2)^2

A=10^3(4)

A=4*10^3

A=4000

4000 bacteria

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -