Question

the system by substitution.
$-x + 3y = 15$
$y = 2x$

Explanation:

Step1: Substitute $y=2x$ into first equation

$-x + 3(2x) = 15$

Step2: Simplify and solve for $x$

$-x + 6x = 15 \\
5x = 15 \\
x = \frac{15}{5} = 3$

Step3: Substitute $x=3$ into $y=2x$

$y = 2(3) = 6$

Answer:

$x=3$, $y=6$