Solving using elimination
-7x-y=-17
7x-5y=-1

x=2, y=3

Step-by-step explanation:

-7x-y=-17

7x-5y=-1

Add the two equations together to eliminate x

-7x-y=-17

7x-5y=-1

  -6y = -18

Divide by -6

-6y/-6 = -18/-6

y = 3

Now we need to find x

7x -5y = -1

7x -5(3) = -1

7x -15 = -1

Add 15 to each side

7x -15+15 = -1+15

7x = 14

Divide by 7

7x/7 = 14/7

x =2

the correct answer is 5 6 and 7

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!