Question

pleas help someone, step by step=
5x+y+3=-14=8y-x
x+2x=y+4
substitution method

Answer 1

In the substitution we want to either express x in terms of y, or y in terms of x so that we can get numerical answers.
So... lets begin!
\[5x+y+3=-14-8y-x\]
\[x+2x=y+4\]
I'm going to first start by simplifying the second equation:
\[x+2x=y+4\]
\[3x=y+4\] (x+2x is equal to 3x)
\[3x-4=y\]
(moving 4 to the right side by subtracting 4 from both sides)

So, now we know that y is equal to the value of 3x's minus four, so lets plug in 3x-4 in for every "y" in the first equation

Answer 2

Knowing \[y=3x-4\]
I'm going to plug that in for every "y" in the first equation.
So... let's do that.
-----
\[5x+y+3=-14-8y-x\]|
Original equation
\[5x+(3x-4)+3=-14-(8(3x-4))-x\]
Substituted 3x-4 for every "y" in the equation

\[5x+(3x-4)+3=-14-(24x-32)-x\]
Simplified 8 times 3x-4
\[5x+3x-4+3=-14-24x-32-x\]
Removed parenthesis
\[8x-1=-14-24x-32-x\]
5x+3x is 8x, 3-4 is -1 (so more simplification)
\[8x-1=-46-23x\]
-14-32 is -46, 24x-x is 23x (so I simplified the right hand side)

Answer 3

\[8x-1=-46-23x\]
(Recopied equation from last post)
\[8x=-45-23x\]
Added 1 to both sides
\[31x=-45\]
Added 23x to both sides
\[x=\frac{-45}{31}\]
Divide both sides by 31 to get x by its self.

Answer 4

So now we know that

\[x=\frac{-45}{31}\]
Let's revisit the equation we simplified in the very beginning:
\[y=3x-4\]
Now that we know what the value of x is, we just simply plug in that value into the equation and solve for y!

Answer 5

ok, p

Answer 6

im working on it

Answer 7

y= y=134/31-4

Answer 8

Yep. so:
\[y=\frac{131}{31}-4\]
\[x=-\frac{45}{31}\]

Answer 9

so is that the final answer