What is the answer to 7/5 = x/(9-x) ?

The answer to 7/5 = x/(9-x) is x= 21/4

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7/5 = x/(9-x)

\frac{7}{5} = \frac{x}{9 - x}

x = \frac{21}{4}

Decimal Notation

x = 5.25

Solution steps

\frac{7}{5} = \frac{x}{9 - x}

Cross multiply

63 - 7 x = 5 x

Move

63

to the right side

- 7 x = 5 x - 63

Move

5 x

to the left side

- 12 x = - 63

Divide both sides by

- 12

x = \frac{21}{4}

Verify Solutions

Find undefined (singularity) points:

x = 9

Combine undefined points with solutions:

x = \frac{21}{4}

x + \frac{1}{x} = c + \frac{1}{c}

\frac{x}{x - 3} + 8 = \frac{3}{x - 3}

\frac{5}{y - 4} - \frac{2}{3 y + 1} = 0

\frac{9}{x + 1} + 3 = - 3

\frac{1 + a}{1 - a} = \frac{- 2}{z}