Solve {l}{-8r-3=-5r+9}{s=r}{t=s}{text{Solvefor}utext{where}}{u=t}

$$\left. \begin{array} { l } { -8 r - 3 = -5 r + 9 }\\ { s = r }\\ { t = s }\\ { \text{Solve for } u \text{ where} } \\ { u = t } \end{array} \right.$$

Solve for r, s, t, u

$$u=-4$$

Solution Steps

Consider the first equation. Add 5r to both sides.

$$-8r-3+5r=9$$

Combine -8r and 5r to get -3r.

$$-3r-3=9$$

Add 3 to both sides.

$$-3r=9+3$$

Add 9 and 3 to get 12.

$$-3r=12$$

Divide both sides by -3.

$$r=\frac{12}{-3}$$

Divide 12 by -3 to get -4.

$$r=-4$$

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

$$s=-4$$

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

$$t=-4$$

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

$$u=-4$$

The system is now solved.

$$r=-4 s=-4 t=-4 u=-4$$