multiply and divide rational numbers quick check

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Here's a quick guide on how to multiply and divide rational numbers:

Multiplying Rational Numbers

  1. Multiply the Numerators: Multiply the top numbers (numerators) together.
  2. Multiply the Denominators: Multiply the bottom numbers (denominators) together.
  3. Simplify if Necessary: If the resulting fraction can be simplified, do so.

Example: \[ \frac{2}{3} \times \frac{4}{5} = \frac{2 \times 4}{3 \times 5} = \frac{8}{15} \]

Dividing Rational Numbers

  1. Multiply by the Reciprocal: Instead of dividing by a fraction, multiply by its reciprocal (flip the second fraction).
  2. Follow Multiplication Steps: Then use the multiplication steps (multiply numerators and denominators).
  3. Simplify if Necessary: If the resulting fraction can be simplified, do so.

Example: \[ \frac{2}{3} \div \frac{4}{5} = \frac{2}{3} \times \frac{5}{4} = \frac{2 \times 5}{3 \times 4} = \frac{10}{12} = \frac{5}{6} \text{ (simplified)} \]

Quick Tips

  • Simplify Early: If you can simplify fractions before multiplying/dividing, it can make calculations easier.
  • Negative Signs: Remember that a negative times a negative is a positive, and a negative times a positive (or vice versa) is a negative.
  • Always ensure your final answer is in its simplest form.

If you have specific problems or examples you want help with, feel free to provide them!