Solve {l}{x-y=8}{y=-4}{z=x-3}{text{Solvefor}atext{where}}{a=z}

$$\left. \begin{array} { l } { x - y = 8 }\\ { y = -4 }\\ { z = x - 3 }\\ { \text{Solve for } a \text{ where} } \\ { a = z } \end{array} \right.$$

Solve for x, y, z, a

$$a=1$$

Solution Steps

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

$$x-\left(-4\right)=8$$

Multiply -1 and -4 to get 4.

$$x+4=8$$

Subtract 4 from both sides.

$$x=8-4$$

Subtract 4 from 8 to get 4.

$$x=4$$

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

$$z=4-3$$

Subtract 3 from 4 to get 1.

$$z=1$$

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

$$a=1$$

The system is now solved.

$$x=4 y=-4 z=1 a=1$$