Solve {l}{18=15-x}{27x+9=y}

$$\left. \begin{array} { l } { 18 = 15 - x } \\ { 27 x + 9 = y } \end{array} \right.$$

Solve for x, y

$$x=-3$$

$$y=-72$$

Solution Steps

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

$$15-x=18$$

Subtract 15 from both sides.

$$-x=18-15$$

Subtract 15 from 18 to get 3.

$$-x=3$$

Divide both sides by -1.

$$x=-3$$

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

$$27\left(-3\right)+9=y$$

Multiply 27 and -3 to get -81.

$$-81+9=y$$

Add -81 and 9 to get -72.

$$-72=y$$

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

$$y=-72$$

The system is now solved.

$$x=-3 y=-72$$