S K Gupta and Anubhuti Gangal Solutions for Exercise 2: EXERCISE 2 (B)

Compare: Fill in the blanks $<, >$ or $=$

$7\times {10}^{-20}$ _____ $9\times {10}^{-21}$​​​​​​

${\left[4^{-1}+6^{-1}+8^{-1}\right]}^0$ equals​​​​​​

If $x={\left(\frac{5}{8}\right)}^{-2}\times {\left(\frac{12}{15}\right)}^{-2}$ then the value of $x^{-3}$ is 

Solve for $x: {81}^{-2}÷{729}^{1-x}=9^{2x}$

The thickness of  a soap bubble is about $0.000004 metres$. Write the thickness in scientific notation.

$\left(6\times {10}^{-2}+4.9\times {10}^{-4}\right)$ equals

Simplify $\frac{1}{1+a^{n-m}}+\frac{{\displaystyle 1}}{{\displaystyle 1+a^{m-n}}}$

Simplify: 

$\frac{{\left(x^{a+b}\right)}^2\times {\left(x^{b+c}\right)}^2\times {\left(x^{c+a}\right)}^2}{{\left(x^a.x^b.x^c\right)}^3}$