Solve the equation.

two thirds plus one fifth x minus one fourth equals four fifths x

1 answer

To solve the equation

\[ \frac{2}{3} + \frac{1}{5}x - \frac{1}{4} = \frac{4}{5}x, \]

let's first rearrange the equation to isolate all terms involving \(x\) on one side and constant terms on the other side.

  1. Start by simplifying the equation:

\[ \frac{1}{5}x - \frac{4}{5}x = -\frac{2}{3} + \frac{1}{4}. \]

  1. Combine the \(x\) terms:

\[ \frac{1 - 4}{5}x = -\frac{2}{3} + \frac{1}{4}. \]

This simplifies to:

\[ -\frac{3}{5}x = -\frac{2}{3} + \frac{1}{4}. \]

  1. Now we need a common denominator to combine the constants on the right side. The least common multiple of 3 and 4 is 12. Rewrite \(-\frac{2}{3}\) and \(\frac{1}{4}\):

\[ -\frac{2}{3} = -\frac{8}{12}, \] \[ \frac{1}{4} = \frac{3}{12}. \]

So we have:

\[ -\frac{3}{5}x = -\frac{8}{12} + \frac{3}{12}. \]

Now combine the fractions on the right:

\[ -\frac{3}{5}x = -\frac{8 - 3}{12} = -\frac{5}{12}. \]

  1. Now we can multiply both sides by -1:

\[ \frac{3}{5}x = \frac{5}{12}. \]

  1. To isolate \(x\), multiply both sides by the reciprocal of \(\frac{3}{5}\), which is \(\frac{5}{3}\):

\[ x = \frac{5}{12} \cdot \frac{5}{3} = \frac{25}{36}. \]

Thus, the solution to the equation is

\[ \boxed{\frac{25}{36}}. \]