Question

B^ - 7 /B ^- 4 Б ^- 2 если B=-1/5​

Answer 1

$\frac{ - \frac{1}{5}^{ - 7} }{ - \frac{1}{5}^{ - 4} \times ( - \frac{1}{5}^{ - 2}) } = - \frac{ \frac{1}{5}^{ - 7} }{ \frac{1}{5}^{ - 6} } = - \frac{1}{ \frac{1}{5} } = - 5$

Ответ: –5.

Answer 2

To calculate the expression $B^{-7} / B^{-4} \times B^{-2}$ given $B = -1/5$, we can substitute $B$ with $-1/5$ and perform the calculations step by step:

1. Substitute $B$ with $-1/5$:

   $$(-1/5)^{-7} / (-1/5)^{-4} \times (-1/5)^{-2}$$

2. Use the property $a^{-n} = 1 / a^n$:

   $$(1 / (-1/5)^7) / (1 / (-1/5)^4) \times (1 / (-1/5)^2)$$

3. Simplify using the rule $1 / (a / b) = b / a$:

   $$(-1/5)^4 / (-1/5)^7 \times (-1/5)^2$$

4. Use the rule $a^m \times a^n = a^{m+n}$:

   $$(-1/5)^{4 + (-7)} \times (-1/5)^2$$

5. Simplify the exponents:

   $$(-1/5)^{-3} \times (-1/5)^2$$

6. Use the rule $a^m \times a^n = a^{m+n}$:

   $$(-1/5)^{-3 + 2}$$

7. Simplify the exponent:

   $$(-1/5)^{-1}$$

8. Use the property $a^{-1} = 1 / a$:

   $$-1 / (-1/5)$$

9. Simplify the expression by multiplying by the reciprocal:

   $$-1 / (-1/5) = 5$$

So, $B^{-7} / B^{-4} \times B^{-2}$ when $B = -1/5$ is equal to $5$.