Solve {l}{4-2y=7y+13}{z=y}{text{Solvefor}atext{where}}{a=z}

$$\left. \begin{array} { l } { 4 - 2 y = 7 y + 13 }\\ { z = y }\\ { \text{Solve for } a \text{ where} } \\ { a = z } \end{array} \right.$$

Solve for y, z, a

$$a=-1$$

Solution Steps

Consider the first equation. Subtract 7y from both sides.

$$4-2y-7y=13$$

Combine -2y and -7y to get -9y.

$$4-9y=13$$

Subtract 4 from both sides.

$$-9y=13-4$$

Subtract 4 from 13 to get 9.

$$-9y=9$$

Divide both sides by -9.

$$y=\frac{9}{-9}$$

Divide 9 by -9 to get -1.

$$y=-1$$

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

$$z=-1$$

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

$$a=-1$$

The system is now solved.

$$y=-1 z=-1 a=-1$$