Solve {l}{12+3y=4x}{12=-y}

$$\left\{ \begin{array}{l}{ 12 + 3 y = 4 x }\\{ 12 = - y }\end{array} \right.$$

Solve for y, x

$$x=-6$$

$$y=-12$$

Solution Steps

Consider the second equation. Swap sides so that all variable terms are on the left hand side.

$$-y=12$$

Divide both sides by -1.

$$y=-12$$

Consider the first equation. Insert the known values of variables into the equation.

$$12+3\left(-12\right)=4x$$

Multiply 3 and -12 to get -36.

$$12-36=4x$$

Subtract 36 from 12 to get -24.

$$-24=4x$$

Swap sides so that all variable terms are on the left hand side.

$$4x=-24$$

Divide both sides by 4.

$$x=\frac{-24}{4}$$

Divide -24 by 4 to get -6.

$$x=-6$$

The system is now solved.

$$y=-12 x=-6$$