Exponents and P...

$${ \left( \dfrac { -1 }{ 2 }  \right)  }^{ -3 }=?$$

$${ \left( \dfrac { -5 }{ 3 }  \right)  }^{ -1 }=?$$

$$(-3/7)^{-1} = ?$$

$$\left\{ \left( \dfrac { 1 }{ 3 }  \right) ^{ -3 }-\quad \left( \dfrac { 1 }{ 2 }  \right) ^{ -3 } \right\} \div \quad \left( \dfrac { 1 }{ 4 }  \right) ^{ -3 }=?$$

Mark tick against the correct answer in each of the following:
$$(6^{-1}-8^{-1})^{-1}=$$?

Mark tick against the correct answer in each of the following:
$$(-1/2)^{-6}=$$?

Mark tick against the correct answer in each of the following:
$$\left\{(3/4)^{-1}+(1/4)^{-1}\right\}^{-1}=$$?

The value of $$\dfrac {1}{4^{-2}}$$ is

For a fixed base(10) if the exponent decreases by $$1$$, the number becomes

Mark tick against the correct answer of the following:
$$\left(\dfrac23\right)^{-5}=$$?