1. Evaluate expression 13: $24 - 7 [ -5^2 - 4(3 - 9) - 49 \div (-7) ]$ - Calculate inside brackets: - $-5^2 = -(5^2) = -25$ - $3 - 9 = -6$ - $-4 \times (-6) = +24$ - $49 \div (-7) = -7$ - So inside brackets: $-25 - 24 - (-7) = -25 - 24 + 7 = -42$ - Now: $24 - 7 \times (-42) = 24 + 294 = 318$ 2. Evaluate expression 14: $-13^2 - 2 [ -5(15 - 6) \div 9 + 8(-5 - 3) ]$ - Calculate powers and parentheses: - $-13^2 = -(169) = -169$ - $15 - 6 = 9$ - $-5 \times 9 = -45$ - $-45 \div 9 = -5$ - $-5 - 3 = -8$ - $8 \times (-8) = -64$ - Inside brackets: $-5 + (-64) = -69$ - Multiply by $-2$: $-2 \times (-69) = 138$ - Sum: $-169 + 138 = -31$ 3. Evaluate expression 15: $-2 [ ( -4 + 5 ) \div 2 ]^3 + (9 - 6 \times 2 + 2)$ - Calculate inside first bracket: - $-4 + 5 = 1$ - $1 \div 2 = 0.5$ - Cube: $(0.5)^3 = 0.125$ - Multiply by $-2$: $-2 \times 0.125 = -0.25$ - Calculate inside second parentheses: - $6 \times 2 = 12$ - $9 - 12 + 2 = -1$ - Sum: $-0.25 + (-1) = -1.25$ 4. Evaluate expression 16: $- \frac{1}{4} - ( - \frac{3}{7} )$ - Simplify: $-\frac{1}{4} + \frac{3}{7} = \frac{-7}{28} + \frac{12}{28} = \frac{5}{28}$ 5. Evaluate expression 17: $\frac{2}{5} - \left( + \frac{6}{7} \right)$ - Simplify: $\frac{2}{5} - \frac{6}{7} = \frac{14}{35} - \frac{30}{35} = -\frac{16}{35}$ 6. Evaluate expression 18: $- \frac{5}{7} - ( - 2 \frac{3}{8} )$ - Convert mixed number: $2 \frac{3}{8} = \frac{19}{8}$ - Simplify: $-\frac{5}{7} + \frac{19}{8} = \frac{-40}{56} + \frac{133}{56} = \frac{93}{56} = 1 \frac{37}{56}$ 7. Evaluate expression 19: $2 \frac{1}{5} - ( - 4 \frac{5}{6} )$ - Convert mixed numbers to improper fractions: - $2 \frac{1}{5} = \frac{11}{5}$ - $4 \frac{5}{6} = \frac{29}{6}$ - Simplify: $\frac{11}{5} + \frac{29}{6} = \frac{66}{30} + \frac{145}{30} = \frac{211}{30} = 7 \frac{1}{30}$ 8. Evaluate expression 20: $3 + ( - \frac{5}{6} ) - 1 \frac{3}{4}$ - Convert mixed number: $1 \frac{3}{4} = \frac{7}{4}$ - Simplify stepwise: - $3 - \frac{5}{6} = \frac{18}{6} - \frac{5}{6} = \frac{13}{6}$ - $\frac{13}{6} - \frac{7}{4} = \frac{26}{12} - \frac{21}{12} = \frac{5}{12}$ 9. Evaluate expression 21: $4 - ( - 1 \frac{3}{8} ) - 5 \frac{1}{8}$ - Convert mixed numbers: - $1 \frac{3}{8} = \frac{11}{8}$ - $5 \frac{1}{8} = \frac{41}{8}$ - Simplify: - $4 + \frac{11}{8} = \frac{32}{8} + \frac{11}{8} = \frac{43}{8}$ - $\frac{43}{8} - \frac{41}{8} = \frac{2}{8} = \frac{1}{4}$ 10. Evaluate expression 22: $8 \times \left( - \frac{3}{4} \right) = -6$ 11. Evaluate expression 23: $\frac{4}{15} \div \left( - \frac{1}{3} \right) = \frac{4}{15} \times \left( -3 \right) = -\frac{12}{15} = -\frac{4}{5}$ 12. Evaluate expression 24: $(-3) \div \left( - \frac{3}{5} \right) \times \frac{7}{15}$ - Simplify division: $-3 \div -\frac{3}{5} = -3 \times -\frac{5}{3} = 5$ - Multiply: $5 \times \frac{7}{15} = \frac{35}{15} = \frac{7}{3}$ 13. Evaluate expression 25: $\left( - \frac{1}{4} \right) \times 80 \div \left( - \frac{4}{5} \right)$ - Calculate multiplication: $-\frac{1}{4} \times 80 = -20$ - Divide by $-\frac{4}{5}$: $-20 \div -\frac{4}{5} = -20 \times -\frac{5}{4} = 25$