# How do you solve y = 1 - 5x and 5x + y = 8 using substitution?

You take the value of one variable in one equation and put it in other. Here as $y = 1 - 5 x$, putting it in $5 x + y = 8$ gives us
$5 x + 1 - 5 x = 8$ or $1 = 8$. As this is not possible, there is no solution.