Asurvey of 2000 doctors showed that an average of 3 out of 5 doctors is brand x aspirin. how many doctors use brand x aspirin

since, average of  doctors using brand x aspirin  is 3 out of 5

if we consider one part then one part will be equal to 3/5

total survey consists of 2000 doctors then to find the brand x aspirin we can use the unitary method that is  multiply the total number by one part

2000 x 3/5= 400 x 3

= 1200

so, total 1200 doctors are using brand x aspirin

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!