29. For all values of X, x^2+2x+4 = (x + 2)^2 + a(x+2) + b,
where a and b are constants. What is the value
of a?
(A) -2
(b) - 1
(c) 0
(d) 1​

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!