CPM Homework Help : INT3 Problem 1-41

Where is the error in the solution below? Explain what the error is and solve the equation correctly. Be sure to check your answer.

$\left. \begin{array}{l}{ \frac { 5 } { x } = x - 4 }\\{ x \cdot \frac { 5 } { x } = x - 4 }\\{ 5 = x - 4 }\\{ x = 9 }\end{array} \right.$

Hint:

Is the equation on line 2 equivalent to line 1?

Help:

What is the problem on line 2? What do you need to do to fix it?

More Help 1:

Multiply both sides of the equation, making a note that $x\ne0$ .

More Help 2:

You now have a quadratic equation to solve.

Answers:

$x = −1$ or $x = 5$