Solve {l}{x=10}{y=-12}{z=2x+3y-4}{text{Solvefor}atext{where}}{a=z}

$$\left. \begin{array} { l } { x = 10 }\\ { y = -12 }\\ { z = 2 x + 3 y - 4 }\\ { \text{Solve for } a \text{ where} } \\ { a = z } \end{array} \right.$$

Solve for x, y, z, a

$$a=-20$$

Solution Steps

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

$$z=2\times 10+3\left(-12\right)-4$$

Do the multiplications.

$$z=20-36-4$$

Subtract 36 from 20 to get -16.

$$z=-16-4$$

Subtract 4 from -16 to get -20.

$$z=-20$$

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

$$a=-20$$

The system is now solved.

$$x=10 y=-12 z=-20 a=-20$$