How do I solve for x in the equation y=-x+4?

Question

pooja195 · Answer

Ok so you said
y-4=x

anonymous · Answer

No, y-4 = -x

pooja195 · Answer

^right
divide everything by -1  what are you left with?

anonymous · Answer

y+4 = x
so x= y+4 right ?

pooja195 · Answer

Well the y was orginally positive  so y/-1= ?

anonymous · Answer

I have to do substitution 
The page says to solve each system by substitution 
The problem is y=-x+4
and then y=3x

anonymous · Answer

I have to solve for x and then substitute it into the other equation.

pooja195 · Answer

ooohhh that makes sense  
 y=-x+4 <---equation 1  
  y=3x <---equation 2 
We know the value of y take equation 1 and plug it into equation 2

 $$\huge~\rm~\bf~\color{blue}{  x+4}=3x$$
Solve for x

pooja195 · Answer

Are you stuck?

pooja195 · Answer

Start by subtracting x from both sides
 $$\huge~\rm~ x- x+4=3x-x$$

pooja195 · Answer

$$\huge~\rm~ 4=3x-x$$
3x-x=?

anonymous · Answer

its y = -x+4 not x+4

pooja195 · Answer

ooohhh that makes sense  
 y=-x-4 <---equation 1  
  y=3x <---equation 2 
We know the value of y take equation 1 and plug it into equation 2

 $$\huge~\rm~\bf~\color{blue}{  x-4}=3x$$
Solve for x
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