Two window washers, william and alan, lean a ladder against the side of a building so that william can wash a window while alan holds the ladder. the top of the ladder reaches the window, which is 16 feet off the ground. the base of the ladder is 12 feet away from the building. how long is the ladder?

i got 10.28 but that rounds up to 10.3

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!