Solve {l}{-5*9x-5*21=9}{y=54}{text{Solvefor}ztext{where}}{z=y}

$$\left. \begin{array} { l } { -5 \cdot 9 x - 5 \cdot 21 = 9 }\\ { y = 54 }\\ { \text{Solve for } z \text{ where} } \\ { z = y } \end{array} \right.$$

Solve for x, y, z

$$z=54$$

Solution Steps

Consider the first equation. Multiply -5 and 9 to get -45.

$$-45x-5\times 21=9$$

Multiply 5 and 21 to get 105.

$$-45x-105=9$$

Add 105 to both sides.

$$-45x=9+105$$

Add 9 and 105 to get 114.

$$-45x=114$$

Divide both sides by -45.

$$x=\frac{114}{-45}$$

Reduce the fraction \frac{114}{-45} to lowest terms by extracting and canceling out 3.

$$x=-\frac{38}{15}$$

The system is now solved.

$$x=-\frac{38}{15} y=54 z=54$$