Solve {l}{4x+7=85}{y=x}{text{Solvefor}ztext{where}}{z=y}

$$\left. \begin{array} { l } { 4 x + 7 = 85 }\\ { y = x }\\ { \text{Solve for } z \text{ where} } \\ { z = y } \end{array} \right.$$

Solve for x, y, z

$$z = \frac{39}{2} = 19\frac{1}{2} = 19.5$$

Solution Steps

Consider the first equation. Subtract 7 from both sides.

$$4x=85-7$$

Subtract 7 from 85 to get 78.

$$4x=78$$

Divide both sides by 4.

$$x=\frac{78}{4}$$

Reduce the fraction \frac{78}{4} to lowest terms by extracting and canceling out 2.

$$x=\frac{39}{2}$$

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

$$y=\frac{39}{2}$$

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

$$z=\frac{39}{2}$$

The system is now solved.

$$x=\frac{39}{2} y=\frac{39}{2} z=\frac{39}{2}$$