# How do you solve x=4y and x=y-3  using substitution?

Mar 16, 2016

$x , y = - 4 , - 1$

#### Explanation:

color(blue)(x=4y,x=y-3

Substitute the value of $x$ to the second equation

$\rightarrow 4 y = y - 3$

$\rightarrow 4 y = y = - 3$

$\rightarrow 3 y = - 3$

rArrcolor(green)(y=-3/3=-1

Substitute the value of $y$ to the first equation

$\rightarrow x = 4 \left(- 1\right)$

rArrcolor(green)(x=-4

$\therefore \textcolor{g r e e n}{| \overline{\underline{x , y = - 4 , - 1}}} |$