Зариант 2 -1,2-6 -7,2:0,36 3) 0,3-5,62 4) 4,2+(-0,39) 5)-2-9 316 6):(-0,2) 7)-2-(-3) 3 8)-3-+2,9 9) (4) 4 4* 10) (-5)-25:(-5') 11) 2,7-10-1,3 3,9-10-5,4 12) 4-1,44-2-16 2 часть 13) Вырази и из U формулы А=1. R 14) Вычисли или упрости (3-1) 15) Вычисли или упрости 2-2√2 √2-1 16) Сократи дробь y-16 4√y + y y+y 2

1) \[ -1.2 \cdot 6 \]

\[ -1.2 \cdot 6 = -7.2 \]

2) \[ -7.2 : 0.36 \]

\[ -7.2 : 0.36 = -20 \]

3) \[ 0.3 - 5.62 \]

\[ 0.3 - 5.62 = -5.32 \]

4) \[ 4.2 + (-0.39) \]

\[ 4.2 + (-0.39) = 3.81 \]

5) \[ -\frac{2}{3} \cdot (-\frac{9}{16}) \]

\[ -\frac{2}{3} \cdot (-\frac{9}{16}) = \frac{2 \cdot 9}{3 \cdot 16} = \frac{18}{48} = \frac{3}{8} \]

6) \[ \frac{1}{2} : (-0.2) \]

\[ \frac{1}{2} : (-0.2) = \frac{1}{2} : (-\frac{1}{5}) = \frac{1}{2} \cdot (-5) = -\frac{5}{2} = -2.5 \]

7) \[ -2\frac{7}{9} - (-3\frac{1}{2}) \]

\[ -2\frac{7}{9} - (-3\frac{1}{2}) = -2\frac{7}{9} + 3\frac{1}{2} = -\frac{25}{9} + \frac{7}{2} = \frac{-25 \cdot 2 + 7 \cdot 9}{18} = \frac{-50 + 63}{18} = \frac{13}{18} \]

8) \[ -3\frac{3}{5} + 2.9 \]

\[ -3\frac{3}{5} + 2.9 = -3.6 + 2.9 = -0.7 \]

9) \[ \frac{(4^3)^2 \cdot 4^4}{4^8} \]

\[ \frac{(4^3)^2 \cdot 4^4}{4^8} = \frac{4^6 \cdot 4^4}{4^8} = \frac{4^{10}}{4^8} = 4^{10-8} = 4^2 = 16 \]

10) \[ (-5)^2 - 25 : (-5^3) \]

\[ (-5)^2 - 25 : (-5^3) = 25 - 25 : (-125) = 25 - (-\frac{25}{125}) = 25 + \frac{1}{5} = 25.2 \]

11) \[ \frac{2.7 \cdot 10^5 \cdot 1.3}{3.9 \cdot 10^4 \cdot 5.4} \]

\[ \frac{2.7 \cdot 10^5 \cdot 1.3}{3.9 \cdot 10^4 \cdot 5.4} = \frac{2.7 \cdot 1.3 \cdot 10}{3.9 \cdot 5.4} = \frac{2.7 \cdot 1.3 \cdot 10}{3.9 \cdot 5.4} = \frac{35.1}{21.06} = \frac{3510}{2106} = \frac{5}{3} \approx 1.67 \]

12) \[ 4 \cdot \sqrt{1.44} - 2 \cdot \sqrt{16} \]

\[ 4 \cdot \sqrt{1.44} - 2 \cdot \sqrt{16} = 4 \cdot 1.2 - 2 \cdot 4 = 4.8 - 8 = -3.2 \]

13) Выразить U из формулы \[ A = \frac{U^2}{R} \cdot t \]

\[ A = \frac{U^2}{R} \cdot t \Rightarrow U^2 = \frac{A \cdot R}{t} \Rightarrow U = \sqrt{\frac{A \cdot R}{t}} \]

14) Вычислить или упростить \[ \sqrt{(3 - \sqrt{11})^2} \]

\[ \sqrt{(3 - \sqrt{11})^2} = |3 - \sqrt{11}| = \sqrt{11} - 3 \]

15) Вычислить или упростить \[ \frac{2}{\sqrt{2} - 1} - 2\sqrt{2} \]

\[ \frac{2}{\sqrt{2} - 1} - 2\sqrt{2} = \frac{2(\sqrt{2} + 1)}{(\sqrt{2} - 1)(\sqrt{2} + 1)} - 2\sqrt{2} = \frac{2(\sqrt{2} + 1)}{2 - 1} - 2\sqrt{2} = 2\sqrt{2} + 2 - 2\sqrt{2} = 2 \]

16) Сократить дробь \[ \frac{y - 16}{4\sqrt{y} + y} \]

\[ \frac{y - 16}{4\sqrt{y} + y} = \frac{(\sqrt{y} - 4)(\sqrt{y} + 4)}{\sqrt{y}(4 + \sqrt{y})} = \frac{\sqrt{y} - 4}{\sqrt{y}} \]