From 1960 to 1970, the consumer price index (cpi) increased from 29.6 to 48.2. if a dozen donuts cost $0.89 in 1960 and the price of donuts increased at the same rate as the cpi from 1960 to 1970, approximately how much did a dozen donuts cost in 1970?

$19.49‬

Step-by-step explanation:

48.2 - 29.6 = 18.6

18.6 + 0.89 = 19.49

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!