# How do you solve y=3x and x+y=8 using substitution?

Apr 6, 2016

The solution for the system of equations is:
$\textcolor{g r e e n}{x = 2}$

$\textcolor{g r e e n}{y = 6}$

#### Explanation:

color(green)(y= 3 x  ...............equation $\left(1\right)$
$x + y = 8$ ........equation $\left(2\right)$

Substituting equation $1$ in $2 :$

$x + y = 8$

$x + \textcolor{g r e e n}{3 x} = 8$

$4 x = 8$

$x = \frac{8}{4} = 2$

$\textcolor{g r e e n}{x = 2}$

Substituting the value of $x$ in equation $1$ to find $y$:
$y = 3 x$

$y = 3 \cdot \textcolor{g r e e n}{2}$

$\textcolor{g r e e n}{y = 6}$