De 75 estudiantes de un aula, los 3/5 usa reloj; 1/3 de los estudiantes sólo usa anteojos; los 2/5 usan anteojos y reloj ¿Cuántos no usan anteojos ni reloj?

32/80  

91/140

the last one 54 doesn't go into 45. 54/100 ?

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!