Question

$-4x-6-2y=-4y+8y+2$ ,
$2x+4=12$
Consider the system of equations above. If $(x,y)$ is the solution to the system, then what is the value of $x+y$ ?

• A. $-8$
• B. 8
• C. There is no solution to this system of equations

Answer 1

Let's rewrite the equations $-4x-6-2y=-4y+8y+2$ and $2x+4=12$
$-8=4x+6y$
$2x+3y=-4$
Second equation
$2x+4=12$
$2x=8$
$x=4$
Now let’s plug $x=4$ into our simplified version of equation (1)
$2x+3y=-4$
$2\times 4+3y=-4$
$8+3y=-4$
$3y=-12$
$y=-4$
Since $x=4$ & $y=-4$, we can determine that sum is simply, $x+y=0$. The correct answer is 0.