Dereck applies grass seed to 2/5 acre in 3/4 hour. how many acres can derek cover per hour?

Find the unit rate: divide the area by the time. Optionally: convert the given fractions into decimal fractions to speed things up:

0.4 acre

= 0.5333 acre/hour, or 8/15 acre/hour.

0.75 hour

the answer would be 484

step-by-step explanation:

just multiply 0.484 times 1,000 (formula)

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!