An extensive study conducted in 1980 concluded that the mean mercury level in oysters from the White Bear estuary was 0.017 parts per million (ppm) with a standard deviation ppm. In 2012, a sample of 43 oysters from the same estuary exhibited a mean mercury concentration of .

step-by-step explanation:

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!

answer: i literally just answered this question but they want me to do it again

step-by-step explanation: