Question

solving simultaneous equations using substitution practice
complete this assessment to review what youve learned. it will not count toward your grade.
use the substitution method to solve the system $9x - 3y = 12$, $y + 6 = 2x$. (1 point)
check answer remaining attempts: 3

Explanation:

Step1: Isolate $y$ from second equation

Rearrange $y + 6 = 2x$ to solve for $y$:
$y = 2x - 6$

Step2: Substitute $y$ into first equation

Replace $y$ in $9x - 3y = 12$ with $2x - 6$:
$9x - 3(2x - 6) = 12$

Step3: Simplify and solve for $x$

Expand and combine like terms:
$9x - 6x + 18 = 12$
$3x + 18 = 12$
$3x = 12 - 18$
$3x = -6$
$x = \frac{-6}{3} = -2$

Step4: Substitute $x$ to find $y$

Use $y = 2x - 6$ with $x=-2$:
$y = 2(-2) - 6 = -4 - 6 = -10$

Answer:

$x=-2$, $y=-10$