PLEASE HELP

X + Y = 6
X + Y = 4

C. (5,1)

Step-by-step explanation:

Well first we need to single out y in the following equation,

x - y = 4

so,

-x to both sides -y = -x + 4

divide the - by everything y = x - 4.

Now that we have our two equations.

x + y = 6

y = x - 4

We can substitute the y in the x + y = 6 for x - 4

x + x - 4 = 6

2x - 4 = 6

Add the 4

2x = 10

Divide the 2

x = 5.

Now that we have the x we can plug it in for x in x + y = 6

5 + y = 6

-5 to both sides

y = 1

So the solution is (5,1)

For more proof look at the image below.

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!