21. Andre grew a plant for a science experiment. At the end of his experiment, the plant was 100.8 centimeters tall. Andre calculated
that the plant grew an average of 3.6 centimeters per day since
the start of his experiment. How many days did Andre's
experiment last?

he answer is 140 minutes to plant 14 saplings.

Step-by-step explanation:

30 divided by 3=10

so it takes 10 minutes to plant one sapling.

10x14=140 so this is how you get your answer. im 99% sure

100.8÷3.6=28

he grew the plant for 28 days

what is the graph

step-by-step explanation:

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places