# How do you solve the system of equations: x+y=3, 2x-y= -3?

Aug 6, 2015

Add the equations together to get an expression in terms o) $x$, solve for $x$, substitute the solution value back into one of the equations to solve for $y$
$\textcolor{w h i t e}{\text{XXXX}}$$\left(x , y\right) = \left(0 , 3\right)$

#### Explanation:

[1]$\textcolor{w h i t e}{\text{XXXX}}$$x + y = 3$
[2]$\textcolor{w h i t e}{\text{XXXX}}$$2 x - y = - 3$

[3]$\textcolor{w h i t e}{\text{XXXX}}$$3 x = 0$
Solve for $x$
[4]$\textcolor{w h i t e}{\text{XXXX}}$$x = 0$
Substitute $0$ for $x$ in [1] [5]color(white)("XXXX")0 + y = 3#
Solve for $y$
[6]$\textcolor{w h i t e}{\text{XXXX}}$$y = 3$