5. A giraffe is twice as tall as its baby. The baby's height and the mother's height total 4.5m. How tall is the baby? How tall is the mother?

Step-by-step explanation:

call x the mother deer, y the baby deer, we have x = 2y

x + y = 4,5 ---> x = 3, y = 3/2

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!