Solve {l}{4-2x=21}{y=2x+2}{text{Solvefor}ztext{where}}{z=y}

$$\left. \begin{array} { l } { 4 - 2 x = 21 }\\ { y = 2 x + 2 }\\ { \text{Solve for } z \text{ where} } \\ { z = y } \end{array} \right.$$

Solve for x, y, z

$$z=-15$$

Solution Steps

Consider the first equation. Subtract 4 from both sides.

$$-2x=21-4$$

Subtract 4 from 21 to get 17.

$$-2x=17$$

Divide both sides by -2.

$$x=-\frac{17}{2}$$

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

$$y=2\left(-\frac{17}{2}\right)+2$$

Multiply 2 and -\frac{17}{2} to get -17.

$$y=-17+2$$

Add -17 and 2 to get -15.

$$y=-15$$

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

$$z=-15$$

The system is now solved.

$$x=-\frac{17}{2} y=-15 z=-15$$