What is the answer to 21x-4/x =8 ?

The answer to 21x-4/x =8 is x= 2/3 ,x=-2/7

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21x-4/x =8

21 x - \frac{4}{x} = 8

x = \frac{2}{3}, x = - \frac{2}{7}

Decimal Notation

x = 0.66666 \dots, x = - 0.28571 \dots

Solution steps

21 x - \frac{4}{x} = 8

Multiply both sides by

x

21 x^{2} - 4 = 8 x

Solve

21 x^{2} - 4 = 8 x : x = \frac{2}{3}, x = - \frac{2}{7}

x = \frac{2}{3}, x = - \frac{2}{7}

Verify Solutions

Find undefined (singularity) points:

x = 0

Combine undefined points with solutions:

x = \frac{2}{3}, x = - \frac{2}{7}

\frac{x ^{2} - 2 x + 2}{x - 1} = 0

- \frac{2}{c ^{3}} + \frac{3}{4} = 0

x + 24 = - \frac{144}{x}

a + \frac{- 10}{a} = - 3

\frac{1}{2 k ^{2}} = 50