Brian owns bike shop and he rents bikes for $15.
The cost of renting 6 bikes and two skateboards is the
same as renting 4 bikes and 5 skateboards.

How much will it cost you to rent one skateboard and
one bike for you and your little brother ?

$25

Step-by-step explanation:

Say the value of 1 skateboard is x. We can make an equation. 15*6+2x=4*15+5x. 90+2x=60+5x. We can subtract 60 and 2x from both sides to get 30=3x. x=10. The cost of  1 skateboard is 10, so to rent one skateboard and one bike it costs 15+10=$25

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!

i think the amount would be $140.62