Answer:
3m - \frac{4 }{3} - \frac{2 }{ m}
EXPLANATION
The step shown is
\frac{9 {m}^{2} }{3m} - \frac{4m}{3m} - \frac{6}{3m}
This is the same as,
\frac{3 \times 3 \times m \times m }{3 \times m} - \frac{4 \times m}{3 \times m} - \frac{2 \times 3}{3 \times m}
The next thing to do now is to cancel out the common factors to obtain,
\frac{3 \times 1 \times m \times 1 }{1 \times 1} - \frac{4 \times 1}{3 \times 1} - \frac{2 \times 1}{1 \times m}
