Solve {l}{72x+400=100}{100y=30.400}

$$\left. \begin{array} { l } { 72 x + 400 = 100 } \\ { 100 y = 30.400 } \end{array} \right.$$

Solve for x, y

$$x = -\frac{25}{6} = -4\frac{1}{6} \approx -4.166666667$$

$$y=0.304$$

Solution Steps

Consider the first equation. Subtract 400 from both sides.

$$72x=100-400$$

Subtract 400 from 100 to get -300.

$$72x=-300$$

Divide both sides by 72.

$$x=\frac{-300}{72}$$

Reduce the fraction \frac{-300}{72} to lowest terms by extracting and canceling out 12.

$$x=-\frac{25}{6}$$

Consider the second equation. Divide both sides by 100.

$$y=\frac{30.4}{100}$$

Expand \frac{30.4}{100} by multiplying both numerator and the denominator by 10.

$$y=\frac{304}{1000}$$

Reduce the fraction \frac{304}{1000} to lowest terms by extracting and canceling out 8.

$$y=\frac{38}{125}$$

The system is now solved.

$$x=-\frac{25}{6} y=\frac{38}{125}$$