Rational Operations D5B101
1. Calculate the sum or difference of the given rational numbers.
**a)** $\frac{3}{10} + \frac{1}{5}$
- Convert $\frac{1}{5}$ to $\frac{2}{10}$ to have a common denominator.
- Add: $\frac{3}{10} + \frac{2}{10} = \frac{5}{10} = \frac{1}{2}$.
**b)** $2 \frac{1}{3} + (-1 \frac{1}{4})$
- Convert mixed numbers to improper fractions:
$2 \frac{1}{3} = \frac{7}{3}$, $-1 \frac{1}{4} = -\frac{5}{4}$.
- Find common denominator 12:
$\frac{7}{3} = \frac{28}{12}$, $-\frac{5}{4} = -\frac{15}{12}$.
- Add: $\frac{28}{12} - \frac{15}{12} = \frac{13}{12} = 1 \frac{1}{12}$.
**c)** $\frac{5}{12} - \frac{5}{12} = 0$.
**d)** $-2 \frac{1}{2} - (-3 \frac{1}{3})$
- Convert to improper fractions:
$-2 \frac{1}{2} = -\frac{5}{2}$, $-3 \frac{1}{3} = -\frac{10}{3}$.
- Subtracting a negative is adding:
$-\frac{5}{2} + \frac{10}{3}$.
- Common denominator 6:
$-\frac{15}{6} + \frac{20}{6} = \frac{5}{6}$.
**e)** $-\frac{5}{6} + \frac{1}{3}$
- Convert $\frac{1}{3}$ to $\frac{2}{6}$.
- Add: $-\frac{5}{6} + \frac{2}{6} = -\frac{3}{6} = -\frac{1}{2}$.
**f)** $\frac{3}{8} - (-\frac{1}{4})$
- Subtracting a negative is adding:
$\frac{3}{8} + \frac{1}{4}$.
- Convert $\frac{1}{4}$ to $\frac{2}{8}$.
- Add: $\frac{3}{8} + \frac{2}{8} = \frac{5}{8}$.
2. Calculate the sum or difference of the given rational numbers.
**a)** $\frac{2}{3} - \frac{3}{4}$
- Common denominator 12:
$\frac{8}{12} - \frac{9}{12} = -\frac{1}{12}$.
**b)** $-\frac{2}{9} + (-\frac{1}{3})$
- Convert $-\frac{1}{3}$ to $-\frac{3}{9}$.
- Add: $-\frac{2}{9} - \frac{3}{9} = -\frac{5}{9}$.
**c)** $-\frac{1}{4} + (-\frac{3}{5})$
- Common denominator 20:
$-\frac{5}{20} - \frac{12}{20} = -\frac{17}{20}$.
**d)** $-\frac{3}{4} - (-\frac{5}{8})$
- Subtracting a negative is adding:
$-\frac{3}{4} + \frac{5}{8}$.
- Convert $-\frac{3}{4}$ to $-\frac{6}{8}$.
- Add: $-\frac{6}{8} + \frac{5}{8} = -\frac{1}{8}$.
**e)** $1 \frac{1}{2} - 2 \frac{1}{4}$
- Convert to improper fractions:
$\frac{3}{2} - \frac{9}{4}$.
- Common denominator 4:
$\frac{6}{4} - \frac{9}{4} = -\frac{3}{4}$.
**f)** $1 \frac{2}{5} + (-1 \frac{3}{4})$
- Convert to improper fractions:
$\frac{7}{5} - \frac{7}{4}$.
- Common denominator 20:
$\frac{28}{20} - \frac{35}{20} = -\frac{7}{20}$.
3. Calculate the products or quotients.
**a)** $\frac{4}{5} \div \frac{5}{6}$
- Division of fractions: multiply by reciprocal.
- $\frac{4}{5} \times \frac{6}{5} = \frac{24}{25}$.
**b)** $(3 \frac{1}{3})(1 \frac{3}{4})$
- Convert to improper fractions:
$\frac{10}{3} \times \frac{7}{4} = \frac{70}{12} = 5 \frac{10}{12} = 5 \frac{5}{6}$.
**c)** $\frac{1}{8} \times (-\frac{2}{5}) = -\frac{2}{40} = -\frac{1}{20}$.
**d)** $-\frac{9}{10} \div (-\frac{4}{5})$
- Multiply by reciprocal:
$-\frac{9}{10} \times -\frac{5}{4} = \frac{45}{40} = 1 \frac{1}{8}$.
**e)** $-\frac{3}{8} \times 5 \frac{1}{3}$
- Convert $5 \frac{1}{3} = \frac{16}{3}$.
- Multiply:
$-\frac{3}{8} \times \frac{16}{3} = -\frac{48}{24} = -2$.
**f)** $\frac{1}{10} \div (-\frac{3}{8})$
- Multiply by reciprocal:
$\frac{1}{10} \times -\frac{8}{3} = -\frac{8}{30} = -\frac{4}{15}$.
4. Calculate the products or quotients.
**a)** $-\frac{3}{4} \times -\frac{1}{9} = \frac{3}{36} = \frac{1}{12}$.
**b)** $1 \frac{1}{3} \div 1 \frac{1}{4}$
- Convert to improper fractions:
$\frac{4}{3} \div \frac{5}{4} = \frac{4}{3} \times \frac{4}{5} = \frac{16}{15} = 1 \frac{1}{15}$.
**c)** $-\frac{3}{8} \div \frac{7}{10}$
- Multiply by reciprocal:
$-\frac{3}{8} \times \frac{10}{7} = -\frac{30}{56} = -\frac{15}{28}$.
**d)** $-2 \frac{1}{8} \div 1 \frac{1}{4}$
- Convert to improper fractions:
$-\frac{17}{8} \div \frac{5}{4} = -\frac{17}{8} \times \frac{4}{5} = -\frac{68}{40} = -1 \frac{28}{40} = -1 \frac{7}{10}$.
**e)** $\frac{7}{9} \times -\frac{6}{11} = -\frac{42}{99} = -\frac{14}{33}$.
**f)** $-1 \frac{1}{2} \div -2 \frac{1}{2}$
- Convert to improper fractions:
$-\frac{3}{2} \div -\frac{5}{2} = -\frac{3}{2} \times -\frac{2}{5} = \frac{6}{10} = \frac{3}{5}$.
Final answers:
1a) $\frac{1}{2}$
1b) $1 \frac{1}{12}$
1c) $0$
1d) $\frac{5}{6}$
1e) $-\frac{1}{2}$
1f) $\frac{5}{8}$
2a) $-\frac{1}{12}$
2b) $-\frac{5}{9}$
2c) $-\frac{17}{20}$
2d) $-\frac{1}{8}$
2e) $-\frac{3}{4}$
2f) $-\frac{7}{20}$
3a) $\frac{24}{25}$
3b) $5 \frac{5}{6}$
3c) $-\frac{1}{20}$
3d) $1 \frac{1}{8}$
3e) $-2$
3f) $-\frac{4}{15}$
4a) $\frac{1}{12}$
4b) $1 \frac{1}{15}$
4c) $-\frac{15}{28}$
4d) $-1 \frac{7}{10}$
4e) $-\frac{14}{33}$
4f) $\frac{3}{5}$