When using the substitution method, what expression for y in the first equation would be substituted in the second equation?

5x – y = –2
9x + 2y = 23

Question

When using the substitution method, what expression for y in the first equation would be substituted in the second equation?

5x – y = –2
9x + 2y = 23

anonymous · Answer

–5x + 2 /
   5x + 2 /
   –5x – 2 /
   5x – 2

anonymous · Answer

it would be y = 2 +5x

because when you solve for y (in the first equation), you have to subtract 5x and when we do that we get...
-y = -2 - 5x
we can't have a negative variable so we would multiply everything by -1 to get rid of the negative (negative times negative equals a positive)
y = 2 + 5x

anonymous · Answer

y = 5x + 2

anonymous · Answer

yay you explain it too~ thanks :)

anonymous · Answer

NP :) watch this video before anything else http://www.khanacademy.org/video/systems-of-equations?playlist=Algebra

anonymous · Answer

i did! lol. i just don't like math... i am acually doing my sisters work, believe it or not. and i am just getting tired of doing nothing but math prolbem after math problem~

anonymous · Answer

Hey your sister should do her own homework!