Sarah brought $120 to the bookstore. she bought 6 books for $18 each. to find the amount of money, c, that sarah has left, fill in each box with the number that makes each equation true for each of the following steps. step 1: c=120−6⋅ step 2: c=120− step 3: c=

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!