Solve {l}{3x-4=2}{y=3x-21}{z=5}{text{Solvefor}a,btext{where}}{a=y}{b=z}

$$\left. \begin{array} { l } { 3 x - 4 = 2 }\\ { y = 3 x - 21 }\\ { z = 5 }\\ { \text{Solve for } a,b \text{ where} } \\ { a = y }\\ { b = z } \end{array} \right.$$

Solve for x, y, z, a, b

$$a=-15$$

$$b=5$$

Solution Steps

Consider the first equation. Add 4 to both sides.

$$3x=2+4$$

Add 2 and 4 to get 6.

$$3x=6$$

Divide both sides by 3.

$$x=\frac{6}{3}$$

Divide 6 by 3 to get 2.

$$x=2$$

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

$$y=3\times 2-21$$

Multiply 3 and 2 to get 6.

$$y=6-21$$

Subtract 21 from 6 to get -15.

$$y=-15$$

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

$$a=-15$$

The system is now solved.

$$x=2 y=-15 z=5 a=-15 b=5$$