Solve {l}{120-y=12*9}{z=y}{text{Solvefor}atext{where}}{a=z}

$$\left. \begin{array} { l } { 120 - y = 12 \cdot 9 }\\ { z = y }\\ { \text{Solve for } a \text{ where} } \\ { a = z } \end{array} \right.$$

Solve for y, z, a

$$a=12$$

Solution Steps

Consider the first equation. Multiply 12 and 9 to get 108.

$$120-y=108$$

Subtract 120 from both sides.

$$-y=108-120$$

Subtract 120 from 108 to get -12.

$$-y=-12$$

Divide both sides by -1.

$$y=\frac{-12}{-1}$$

Fraction \frac{-12}{-1} can be simplified to 12 by removing the negative sign from both the numerator and the denominator.

$$y=12$$

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

$$z=12$$

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

$$a=12$$

The system is now solved.

$$y=12 z=12 a=12$$