1 uždavinys
Apskaičiuokite
1. $$\frac{7}{15}-\frac{4}{15}$$
Sprendimas.
$$\frac{7}{15}-\frac{4}{15} = \frac{3}{15} = \frac{1}{5}$$
Atsakymas: $$\frac{1}{5}$$
2. $$\frac{5}{28}:(\frac{15}{7})$$
Sprendimas.
$$\frac{5}{28}:(\frac{15}{7}) = \frac{5\cdot 7}{28\cdot 15} = \frac{7}{3\cdot 28} = \frac{1}{3\cdot 4} = \frac{1}{12}$$
Atsakymas: $$\frac{1}{12}$$
3. $$(\frac{2}{3})^{(-3)}$$
Sprendimas.
(
)^(-3) =
| 2 |
| / 3 |
|
(
)^(-3) = $$(\frac{2}{3})^{(-3)}$$ =
| 2 |
| / 3 |
$${\normalsize (\frac{2}{3})^{(-3)}}$$ = $${\normalsize \frac{3^{3}}{2^{3}}}$$
| 3^3 |
| / 2^3 |
$${\normalsize 3^{3}}$$ = $${\normalsize 27}$$
| 27 |
| / 2^3 |
$${\normalsize \frac{1}{2^{3}}}$$ = $${\normalsize \frac{1}{8}}$$
| 27 |
| / 8 |
$$(\frac{2}{3})^{(-3)}$$ = $$$$
$$\frac{3^{3}}{2^{3}}$$ = $$$$
$$\frac{27}{8}$$ $$$$
Atsakymas: $$\frac{27}{8}$$ arba 3 ir $$\frac{3}{8}$$
4. 40 % skaičiaus 115.
Sprendimas.
| 115* 40 |
| / 100 |
|
|
| 115* 40 |
| / 100 |
$${\normalsize \frac{40}{100}}$$ = $${\normalsize \frac{2}{5}}$$
| 115* 2 |
| / 5 |
$${\normalsize \frac{115}{5}}$$ = $${\normalsize 23}$$
| 23* 2 |
| / 1 |
$${\normalsize \frac{23\cdot 2}{1}}$$ = $${\normalsize 46}$$
46$$46$$
$$\frac{115\cdot 40}{100}$$ = $$$$
$$\frac{115\cdot 2}{5}$$ = $$$$
$$\frac{23\cdot 2}{1}$$ = $$$$
$$46$$ $$$$
Atsakymas: $$46$$