Solve {l}{7a-1.8a=3.6}{b=a}{text{Solvefor}ctext{where}}{c=b}

$$\left. \begin{array} { l } { 7 a - 1.8 a = 3.6 }\\ { b = a }\\ { \text{Solve for } c \text{ where} } \\ { c = b } \end{array} \right.$$

Solve for a, b, c

$$c=\frac{9}{13}\approx 0.692307692$$

Solution Steps

Consider the first equation. Combine 7a and -1.8a to get 5.2a.

$$5.2a=3.6$$

Divide both sides by 5.2.

$$a=\frac{3.6}{5.2}$$

Expand \frac{3.6}{5.2} by multiplying both numerator and the denominator by 10.

$$a=\frac{36}{52}$$

Reduce the fraction \frac{36}{52} to lowest terms by extracting and canceling out 4.

$$a=\frac{9}{13}$$

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

$$b=\frac{9}{13}$$

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

$$c=\frac{9}{13}$$

The system is now solved.

$$a=\frac{9}{13} b=\frac{9}{13} c=\frac{9}{13}$$