Triangle r is a right triangle. can we use two copies of triangle r to compose a parallelogram that is not a square.

yes

Step-by-step explanation:

as long as it is not given that the right triangle is isosceles, the two copies of it  will always form a rectangle which is considered a parallelogram, since opposite sides are equal and parallel

it has changed from the width and the height.

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!