287° Вправа 287Алгебра 8 клас Тарасенкова 2025 · § 8 · стор. 84

287. Знайдіть a⁻², якщо a дорівнює:

${\displaystyle a^{-2}=}$${\displaystyle \frac{1}{a^2}}$; для дробу: ${\displaystyle {\left(\frac{a}{b}\right)}^{-2}=}$${\displaystyle {\left(\frac{b}{a}\right)}^2}$ — дріб «перевертаємо».

1) ${\displaystyle 2^{-2}=}$${\displaystyle \frac{1}{2^2}=}$${\displaystyle \frac{1}{4}}$;

2) ${\displaystyle 5^{-2}=}$${\displaystyle \frac{1}{5^2}=}$${\displaystyle \frac{1}{25}}$;

3) ${\displaystyle {10}^{-2}=}$${\displaystyle \frac{1}{100}}$;

4) ${\displaystyle {\left(\frac{1}{2}\right)}^{-2}=}$${\displaystyle 2^2=}$${\displaystyle 4}$;

5) ${\displaystyle {\left(\frac{1}{5}\right)}^{-2}=}$${\displaystyle 5^2=}$${\displaystyle 25}$;

6) ${\displaystyle {\left(\frac{1}{6}\right)}^{-2}=}$${\displaystyle 6^2=}$${\displaystyle 36}$;

7) ${\displaystyle {\left(\frac{1}{10}\right)}^{-2}=}$${\displaystyle {10}^2=}$${\displaystyle 100}$;

8) ${\displaystyle {(-\frac{1}{10})}^{-2}=}$${\displaystyle {\left(-10\right)}^2=}$${\displaystyle 100}$;

9) ${\displaystyle {\left(\frac{1}{100}\right)}^{-2}=}$${\displaystyle {100}^2=}$${\displaystyle 10000}$;

10) ${\displaystyle {(-\frac{1}{100})}^{-2}=}$${\displaystyle {\left(-100\right)}^2=}$${\displaystyle 10000}$.