Question

Solve the system of linear equations by substitution

Answer 1

$y - x = 0 ...equation 1$
$2x - 5y = 9 \: ...equation \: 2$
working with equation 1
$y = x \: ...equation \: 3$
next subsitue equation 3 in equation 1
$2x - 5(x) = 9$
$2x - 5x = 9$
$- 3x = 9$
divide by -3
$x = - 3$
substitute x= -3 in equation 1
$y - ( - 3) = 0$
$-(-3) = + 3$
$y = - 3$