Joe has 76 toothpicks. How many hexagons can he make in a row?
Explain how you figured this out.

Students could also work backwards from 76 toothpicks to find the number of hexagons in a row. 6% could subtract out the first hexagon (76-6) and divide the remainder by 5 (70/5=14), but they forgot to add back on the original hexagon to get 15.

Step-by-step explanation:

true

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!