№1. Раскройте скобки и найдите значение выражения: a)17,24+(7,9-9,14); 6)24,16-(3,9-14,74); 6)-19,47-(-20,69-3,32); 2)-1,8+(-3--5,2); 7 4 4 5 d)-9+3+6 13 26 13' e)817-7-422 39 2 39 -12-+4 2 №4. Упростите выражение и подчеркните коэффициент: a)12a-8b-(-1,5c); -6)-3,8m(-1,6a)-(-3,5n); 4 6)11x(-)-2 2 1 2)-29,4-1 4 p.

№1

a) 17,24 + (7,9 - 9,14) = 17,24 + 7,9 - 9,14 = 25,14 - 9,14 = 16

б) 24,16 - (3,9 - 14,74) = 24,16 - 3,9 + 14,74 = 20,26 + 14,74 = 35

в) -19,47 - (-20,69 - 3,32) = -19,47 + 20,69 + 3,32 = 1,22 + 3,32 = 4,54

г) -1,8 + (-3\(\frac{1}{7}\) - 5,2) = -1,8 - 3\(\frac{1}{7}\) - 5,2 = -1,8 - \(\frac{22}{7}\) - 5,2 = -7 - \(\frac{22}{7}\) = -\(\frac{49}{7}\) - \(\frac{22}{7}\) = -\(\frac{71}{7}\) = -10\(\frac{1}{7}\)

д) -\(\left(9 \frac{4}{13} + 3 \frac{5}{26}\right)\) + 6\(\frac{4}{13}\) = -9 \(\frac{4}{13}\) - 3 \(\frac{5}{26}\) + 6 \(\frac{4}{13}\) = -3 \(\frac{4}{13}\) - 3 \(\frac{5}{26}\) = -3 \(\frac{8}{26}\) - 3 \(\frac{5}{26}\) = -3 \(\frac{13}{26}\) = -3 \(\frac{1}{2}\) = -3,5

е) 8\(\frac{17}{39}\) - \(\left(7 \frac{1}{2} - 4 \frac{22}{39}\right)\) - \(\left(-12 \frac{1}{2} + 4 \frac{5}{9}\right)\) = 8\(\frac{17}{39}\) - 7\(\frac{1}{2}\) + 4\(\frac{22}{39}\) + 12\(\frac{1}{2}\) - 4\(\frac{5}{9}\) = 8\(\frac{17}{39}\) + 4\(\frac{22}{39}\) + 12\(\frac{1}{2}\) - 7\(\frac{1}{2}\) - 4\(\frac{5}{9}\) = 12\(\frac{39}{39}\) + 5 - 4\(\frac{5}{9}\) = 13 + 5 - 4\(\frac{5}{9}\) = 18 - 4\(\frac{5}{9}\) = 13\(\frac{4}{9}\)

№4

a) 12a \(\cdot\) 8b \(\cdot\) (-1,5c) = 12 \(\cdot\) 8 \(\cdot\) (-1,5) \(\cdot\) a \(\cdot\) b \(\cdot\) c = -144abc. Коэффициент: -144

б) -3,8m \(\cdot\) (-1,6a) \(\cdot\) (-3,5n) = -3,8 \(\cdot\) (-1,6) \(\cdot\) (-3,5) \(\cdot\) a \(\cdot\) m \(\cdot\) n = -21,28amn. Коэффициент: -21,28

в) 11\(\frac{4}{7}\)x \(\cdot\) (-\(\frac{2}{9}\)y) \(\cdot\) 2\(\frac{1}{3}\)y = \(\frac{81}{7}\) \(\cdot\) (-\(\frac{2}{9}\)) \(\cdot\) \(\frac{7}{3}\) \(\cdot\) x \(\cdot\) y \(\cdot\) y = -\(\frac{81 \cdot 2 \cdot 7}{7 \cdot 9 \cdot 3}\) \(\cdot\) xy\(^2\) = -\(\frac{18}{3}\)xy\(^2\) = -6xy\(^2\). Коэффициент: -6

г) -29,4 \(\cdot\) (-\(\frac{2}{7}\)k) \(\cdot\) (-\(\frac{1}{4}\)k) \(\cdot\) \(\frac{3}{7}\)p = -29,4 \(\cdot\) \(\frac{2}{7}\) \(\cdot\) \(\frac{1}{4}\) \(\cdot\) \(\frac{3}{7}\) \(\cdot\) k \(\cdot\) k \(\cdot\) p = -\(\frac{29,4 \cdot 2 \cdot 1 \cdot 3}{7 \cdot 4 \cdot 7}\) \(\cdot\) k\(^2\)p = -\(\frac{176,4}{196}\) k\(^2\)p = -0,9 k\(^2\)p. Коэффициент: -0,9