Andrew is showing his work in simplifying (-5.7+2.2)-1.1

step 1 (3.2-5.7)-1.1
step 2 2.2-(5.7+1.1)
step 3 2.2-(6.8)
step 4 -4.6

which statement is true

in step 1, andrew used the commutative property
in step 2, andrew used the distributive property
in step 3, andrew used the associative property
in step 4, andrew's answer is incorrect

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!

if you was gonna solve for a, a is a   < -12