Question

find the solution of the system of equations.
$9x + y = 28$
$3x + 3y = -12$

Explanation:

Step1: Simplify the second equation

Divide the second equation by 3:
$$x + y = -4$$

Step2: Isolate $y$ from simplified eq

Rearrange to solve for $y$:
$$y = -4 - x$$

Step3: Substitute $y$ into first equation

Replace $y$ in $9x + y = 28$:
$$9x + (-4 - x) = 28$$

Step4: Solve for $x$

Simplify and calculate $x$:
$$8x - 4 = 28 \implies 8x = 32 \implies x = 4$$

Step5: Substitute $x$ to find $y$

Use $y = -4 - x$ with $x=4$:
$$y = -4 - 4 = -8$$

Answer:

$x=4$, $y=-8$