Question: 7) (1 - 3/4)(3 - 1/2)=
8 - 5/2 = 6/2 - 5/2 = 3/2 -
8) (7/8)(4/5)(4/7 - 3/4)=
(4/5) x (25/14) - (1/10) x (100/10)
1. **Problem 7:** Calculate $\left(1 - \frac{3}{4}\right)\left(3 - \frac{1}{2}\right)$.
2. Simplify inside the parentheses:
$$1 - \frac{3}{4} = \frac{4}{4} - \frac{3}{4} = \frac{1}{4}$$
$$3 - \frac{1}{2} = \frac{6}{2} - \frac{1}{2} = \frac{5}{2}$$
3. Multiply the simplified terms:
$$\left(\frac{1}{4}\right)\left(\frac{5}{2}\right) = \frac{1 \times 5}{4 \times 2} = \frac{5}{8}$$
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4. **Problem 8:** Calculate $\left(\frac{7}{8}\right)\left(\frac{4}{5}\right)\left(\frac{4}{7} - \frac{3}{4}\right)$.
5. Simplify inside the parentheses:
Find common denominator for $\frac{4}{7}$ and $\frac{3}{4}$ which is $28$:
$$\frac{4}{7} = \frac{16}{28}, \quad \frac{3}{4} = \frac{21}{28}$$
$$\frac{4}{7} - \frac{3}{4} = \frac{16}{28} - \frac{21}{28} = -\frac{5}{28}$$
6. Multiply all terms:
$$\left(\frac{7}{8}\right)\left(\frac{4}{5}\right)\left(-\frac{5}{28}\right) = - \frac{7 \times 4 \times 5}{8 \times 5 \times 28}$$
Cancel common factors:
$$- \frac{\cancel{7} \times 4 \times \cancel{5}}{8 \times \cancel{5} \times 28} = - \frac{4}{8 \times 28}$$
Simplify $\frac{4}{8} = \frac{\cancel{4}}{\cancel{8} \times 2} = \frac{1}{2}$:
$$- \frac{1}{2 \times 28} = - \frac{1}{56}$$
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**Final answers:**
- Problem 7: $\frac{5}{8}$
- Problem 8: $-\frac{1}{56}$