Задание 9. Зная значение данного выражения, найдите значения следующих выражений: A ab=6 1) -ab= 2) 1/2 * ba= 3) ab+ab = 4) ab-10 = 5) 10-ba = 6) 3/ab = 7) -3ab+20 = 8) (20-ab)/7 = 9) (ab)^2 = 10) -(ab)^2 = Б 3k=7 1) 6k=2*3k=2*7=14 2) 3k/10 = 3) 3k/20 = 4) 3k+4 = 5) 9k = 6) 7,7/3k = 7) 50-9k = 8) 1/(-3k) = 9) 2k = 10) 1/5k =

Решение:

Раздел А

Дано: \( ab = 6 \)

1. \( -ab = -6 \)
2. \( \frac{1}{2}ba = \frac{1}{2}ab = \frac{1}{2} \cdot 6 = 3 \)
3. \( ab + ab = 2ab = 2 \cdot 6 = 12 \)
4. \( ab - 10 = 6 - 10 = -4 \)
5. \( 10 - ba = 10 - ab = 10 - 6 = 4 \)
6. \( \frac{3}{ab} = \frac{3}{6} = \frac{1}{2} \)
7. \( -3ab + 20 = -3 \cdot 6 + 20 = -18 + 20 = 2 \)
8. \( \frac{20 - ab}{7} = \frac{20 - 6}{7} = \frac{14}{7} = 2 \)
9. \( (ab)^2 = 6^2 = 36 \)
10. \( -(ab)^2 = -(6^2) = -36 \)

Раздел Б

Дано: \( 3k = 7 \)

1. \( 6k = 2 \cdot 3k = 2 \cdot 7 = 14 \)
2. \( \frac{3k}{10} = \frac{7}{10} \)
3. \( \frac{3k}{20} = \frac{7}{20} \)
4. \( 3k + 4 = 7 + 4 = 11 \)
5. \( 9k = 3 \cdot 3k = 3 \cdot 7 = 21 \)
6. \( \frac{7,7}{3k} = \frac{7,7}{7} = 1,1 \)
7. \( 50 - 9k = 50 - 3 \cdot 3k = 50 - 3 \cdot 7 = 50 - 21 = 29 \)
8. \( \frac{1}{-3k} = \frac{1}{-7} = -\frac{1}{7} \)
9. \( 2k = \frac{2}{3} \cdot 3k = \frac{2}{3} \cdot 7 = \frac{14}{3} \)
10. \( \frac{1}{5k} = \frac{1}{5} \cdot \frac{1}{k} = \frac{1}{5} \cdot \frac{3}{7} = \frac{3}{35} \)

Ответ: А: 1) -6; 2) 3; 3) 12; 4) -4; 5) 4; 6) 1/2; 7) 2; 8) 2; 9) 36; 10) -36. Б: 1) 14; 2) 7/10; 3) 7/20; 4) 11; 5) 21; 6) 1,1; 7) 29; 8) -1/7; 9) 14/3; 10) 3/35.