Solve {l}{x=8}{y=-2}{z={(x-y)}-2{(x-y)}}{text{Solvefor}atext{where}}{a=z}

$$\left. \begin{array} { l } { x = 8 }\\ { y = -2 }\\ { z = {(x - y)} - 2 {(x - y)} }\\ { \text{Solve for } a \text{ where} } \\ { a = z } \end{array} \right.$$

Solve for x, y, z, a

$$a=-10$$

Solution Steps

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

$$z=8-\left(-2\right)-2\left(8-\left(-2\right)\right)$$

Multiply -1 and -2 to get 2.

$$z=8+2-2\left(8-\left(-2\right)\right)$$

Add 8 and 2 to get 10.

$$z=10-2\left(8-\left(-2\right)\right)$$

Multiply -1 and -2 to get 2.

$$z=10-2\left(8+2\right)$$

Add 8 and 2 to get 10.

$$z=10-2\times 10$$

Multiply -2 and 10 to get -20.

$$z=10-20$$

Subtract 20 from 10 to get -10.

$$z=-10$$

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

$$a=-10$$

The system is now solved.

$$x=8 y=-2 z=-10 a=-10$$