SAT Question 65833256: Systems of Linear Equations answer and explanation with Desmos solution

Choice A is correct. The given system of linear equations can be solved by the substitution method. The first equation in the given system of equations defines $y$ as $6x+16$. Substituting $6x+16$ for $y$ in the second equation of the given system of equations yields $-7x-(6x+16)=36$. Applying the distributive property on the left-hand side of this equation yields $-7x-6x-16=36$, or $-13x-16=36$. Adding $16$ to both sides of this equation yields $-13x=52$. Dividing both sides of this equation by $-13$ yields $x=-4$. Substituting $-4$ for $x$ in the first equation of the given system of equations, $y=6x+16$, yields $y=6(-4)+16$, or $y=-8$. Therefore, the solution $(x,y)$ to the given system of equations is $(-4,-8)$.