What is the answer to 7/r = 1/(r-3) ?

The answer to 7/r = 1/(r-3) is r= 7/2

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7/r = 1/(r-3)

\frac{7}{r} = \frac{1}{r - 3}

r = \frac{7}{2}

Decimal Notation

r = 3.5

Solution steps

\frac{7}{r} = \frac{1}{r - 3}

Cross multiply

7 r - 21 = r

Move

21

to the right side

7 r = r + 21

Move

r

to the left side

6 r = 21

Divide both sides by

6

r = \frac{7}{2}

Verify Solutions

Find undefined (singularity) points:

r = 0, r = 3

Combine undefined points with solutions:

r = \frac{7}{2}

0.96 = \frac{0.9 x - 0.3}{0.9 x + 0.1}

\frac{7}{x} = 0.5

\frac{6}{x} = \frac{8}{( x - 1 )}

\frac{3}{x} + 3 + (- 3) = 25 + (- 3)

\frac{- 1}{2 x + 1} = - x + 8