Isolate the variable for x/5=7.5
1 x=35
2 x=1.5
3 x= 37.5
4 x= 2.5

3, x=37.5

Step-by-step explanation:

Since you need to get x alone, you need to get rid of the ÷5. to do this, you need to do the opposite. ×5.

multiply both sides by 5 and you get

x= 7.5(5)

x= 37.5

so the answer would be

3, x=37.5

need more information

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!