Solve {l}{-5/7=x/28}{y=x}{z=y}{text{Solvefor}atext{where}}{a=z}

$$\left. \begin{array} { l } { \frac{-5}{7} = \frac{x}{28} }\\ { y = x }\\ { z = y }\\ { \text{Solve for } a \text{ where} } \\ { a = z } \end{array} \right.$$

Solve for x, y, z, a

$$a=-20$$

Solution Steps

Consider the first equation. Multiply both sides of the equation by 28, the least common multiple of 7,28.

$$4\left(-5\right)=x$$

Multiply 4 and -5 to get -20.

$$-20=x$$

Swap sides so that all variable terms are on the left hand side.

$$x=-20$$

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

$$y=-20$$

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

$$z=-20$$

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

$$a=-20$$

The system is now solved.

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