Question

Use substitution to solve the problem...
x=9y
x+4=5(y+4)
I already now that you can plug x in to the second equation and then distribute but what next?

Answer 1

\[\large \color{orangered}{x=9y}\]\[\large \color{orangered}{x}+4=5(y+4) \qquad \rightarrow \qquad \color{orangered}{9y}+4=5(y+4)\]Distributing gives us,\[\large 9y+4=5y+20\]So you've gotten this much done so far?
Hmm ok.
Subtract 5y from each side,\[9y-5y+4=\cancel{5y-5y}+20\]

Answer 2

\[\large 4y+4=20\]Subtract 4 from each side,\[4y+\cancel{4-4}=20-4\]

Answer 3

Understand the process of combining like terms? :D
That's how the 9y and 5y combined.

Answer 4

You already have the first equation solved for x. So plug in what x is equal to, 9y, into the second equation and solve for y.

Answer 5

yea, now y = 4 and i plug it in to the top equation :) Thanks so much!!

Answer 6

yay good job c:

Answer 7

:D