Question

solve the system using the substitution method. 1. $3x + y = -1$ $2x + 3y = 18$

Explanation:

Step1: Isolate $y$ from first equation

$y = -1 - 3x$

Step2: Substitute $y$ into second equation

$2x + 3(-1 - 3x) = 18$

Step3: Simplify and solve for $x$

$2x - 3 - 9x = 18$
$-7x - 3 = 18$
$-7x = 21$
$x = -3$

Step4: Substitute $x=-3$ into $y$ equation

$y = -1 - 3(-3) = -1 + 9 = 8$

Answer:

$x=-3$, $y=8$