Tan's electricity bill for the month of august was $267.00. his september bill showed a 2% increase from his august bill. in october, his bill decreased 8% from the amount he was billed in august. how much did tan spend on electricity over the tree-month period?

12/11c

or

12

c

11

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!