A researcher randomly divides 50 bean plants into two groups. He puts one group by a window to
receive natural light and the second group under
artificial light. He records the growth of the plants
weekly. Which data collection method is described
in this situation?
1 observational study
2 controlled experiment
3 survey
4 systematic sample

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!

x is the total time in minutes for the free response

you are given number of questions as 15 - m and time per item as 8 minutes

to find x multiply the two givens together:

x = 8 * (15-m) = 8(15-m)

look at photo

answer: 1+1

step-by-step explanation: 1+1 is at least 2