Solve {l}{x-3*3=3x-9}{y=5x-4*6x+5}{text{Solvefor}ztext{where}}{z=y}

$$\left. \begin{array} { l } { x - 3 \cdot 3 = 3 x - 9 }\\ { y = 5 x - 4 \cdot 6 x + 5 }\\ { \text{Solve for } z \text{ where} } \\ { z = y } \end{array} \right.$$

Solve for x, y, z

$$z=5$$

Solution Steps

Consider the first equation. Multiply 3 and 3 to get 9.

$$x-9=3x-9$$

Subtract 3x from both sides.

$$x-9-3x=-9$$

Combine x and -3x to get -2x.

$$-2x-9=-9$$

Add 9 to both sides.

$$-2x=-9+9$$

Add -9 and 9 to get 0.

$$-2x=0$$

Divide both sides by -2. Zero divided by any non-zero number gives zero.

$$x=0$$

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

$$y=5\times 0-4\times 6\times 0+5$$

Multiply 5 and 0 to get 0.

$$y=0-4\times 6\times 0+5$$

Multiply 4 and 6 to get 24.

$$y=0-24\times 0+5$$

Multiply 24 and 0 to get 0.

$$y=0-0+5$$

Subtracting 0 from itself leaves 0.

$$y=0+5$$

Add 0 and 5 to get 5.

$$y=5$$

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

$$z=5$$

The system is now solved.

$$x=0 y=5 z=5$$