How do you evaluate this system of equations: $y-2x=-5; y-x=-3$ ?

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Answer 1 · 2017-06-14T04:34:49

$x=2$ , $y=-1$ ; Ordered Pair: $(2,-1)$

To solve this specific system, the easiest method is substitution.
$y-2x=-5$
$y-x=-3$
Choose one of the equations .. I will pick $y-x=-3$ .
The objective is to get one of the variables ( $x$ or $y$ ) by itself on one side of the equation .. Pick a variable to isolate .. I will pick $y$ .
To isolate $y$ , ADD $x$ to both sides of the equation:
$y-x=-3$
$y=-3+x$
Look at the OTHER equation (the one you did not choose) .. That would be $y-2x=-5$ for me.
See how $y$ is EQUAL to $(-3+x)$ ?
You can substitute the $y$ in $y-2x=-5$ with $(-3+x)$
It should look like this: $(-3+x)-2x=-5$
SIMPLIFY! Now we only have ONE variable in the equation.
$(-3+x)-2x=-5$
$-3-x=-5$
$-x=-2$
$x=2$ [THIS IS THE ANSWER FOR X]
Take one of the equations and substitute $x$ for $2$ to solve for $y$ .
$y-2x=-5$
$y-2(2)=-5$
$y-4=-5$
$y=-1$ [THIS IS THE ANSWER FOR Y]

If your teacher wants it as $(x,y)$ , it is $(2,-1)$ .

How do you evaluate this system of equations: y-2x=-5; y-x=-3y-2x=-5; y-x=-3?