Hey, can someone explain an equation to me step by step? Ill fan and give a Medal.
I have to solve this using substitution, and I'm having a bit of difficulty.
-4 + y = 6
-5x -y = 21
I know the answer is ( -3, -6) Im just having difficulty understanding how you get that answer

Question

Hey, can someone explain an equation to me step by step? Ill fan and give a Medal.
I have to solve this using substitution, and I'm having a bit of difficulty.
-4 + y = 6
-5x -y = 21
I know the answer is ( -3, -6) Im just having difficulty understanding how you get that answer

anonymous · Answer

@Jlockwo3

anonymous · Answer

Do I just change both of the equations to solve for y?

anonymous · Answer

pick the one that does not have both x and y in it

anonymous · Answer

y= 6+4

anonymous · Answer

I have to solve them using substitution, not graphing

anonymous · Answer

then do what we did last time, where we plugged that y= into the equation that has both x and y in it

anonymous · Answer

$$-5x - (10)= 21$$

anonymous · Answer

my bad! she requested by presence

anonymous · Answer

So.. 
y = 6 + 4x
-5x - (6 + 4x) =21

anonymous · Answer

just want to clarify...did you mis type above? was it -4 +y =6   ?

anonymous · Answer

if that is correct. y = 6+4    then    -5x - (10) =21

anonymous · Answer

Oh gosh, Im so sorry. Yes it was. Its 4x + y =6

anonymous · Answer

ok. that changes things... but its not as bad as you think.

anonymous · Answer

change that to y = 6 + 4x and then plug that in, and you were correct in your assumption as noted above

anonymous · Answer

So would the equation then be 6 + 9x = 21

anonymous · Answer

$$-4x + y = 6 --> y= 6+4x--->  -5x- (6+4x)= 21--> -5x - 6 -4x=21$$

anonymous · Answer

you have to distribute that neg sign...

anonymous · Answer

$$-5x-(6+4x)=21  -->  -5x -6 -4x=21$$

anonymous · Answer

Oh, I get it now. Thanks hun!!!

anonymous · Answer

$$-9x = 21+6$$

anonymous · Answer

np

anonymous · Answer

jeez he was rude to me! did he not see that you asked me to come? lol

anonymous · Answer

and he was wrong too lol

anonymous · Answer

TO be honest, my computer has been acting so stupid that the only thing I saw was one second he had made like 10 comments trying to get me to solve this through graphing instead of substitution then next thing I know, all his comment disappeared

anonymous · Answer

he got mad that i started helping you

anonymous · Answer

Goodness, really? He must be new then, usually the members on here try helping each other out explaining the problem at hand instead of fighting over it. He must've really wanted a medal.

anonymous · Answer

lol