HELP PLEASE I need to graduate
A. (-5,-7.2)
B. (-5,-6.8)
C. (-5,6.2)
D.(-5,-5.9)

C

Step-by-step explanation:

You set up a system of equations:

7x-4y=-8 --> -4y=-7x-8 --> y = 7/4 x +2

y = 3/4 x -3 -->

7/4 x + 2 = 3/4 x - 3

7/4x - 3/4x = -3-2

x = -5

That means:

7(-5) - 4y = -8

-35 - 4y = -8

-4y = -27

y = 27/4

y is approx. 6.25, so C is the right answer

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!