Question

1.What is the simplified form of each expression?

Answer 1

Answer with explanation:

Ques 1)

A)

         We are given a expression as:

    $7x^{-8}\times 6x^3$

It could also be written as:

  $(7\times 6)\times x^{-8}\times x^3\\\\\\=42\times x^{-8+3}\\\\\\=42x^{-5}\\\\\\=\dfrac{42}{x^5}$

  Option: a is the answer.

B)

     $(-2x^8)\times 3y^9\times 2x^4$

which is solved as follows:

$(-2\times 3\times 2)\times x^8\times y^9\times x^4\\\\\\=-12x^{8+4}\times y^9\\\\\\=-12x^{12}y^9$

Ques 2)

A)

The expression is:

         $(8\times 10^7)(7\times 10^4)$

It is solved as:

  $=(8\times 7)\times 10^7\times 10^4\\\\\\=56\times 10^{7+4}\\\\\\=56\times 10^{11}\\\\\\=5.6\times 10^{12}$

                 Option: b is the answer.

B)

           $(7\times 10^{-4})(9\times 10^{-10})$

On simplifying:

     $=7\times 9\times 10^{-4}\times 10^{-10}\\\\\\=63\times 10^{-4-10}\\\\\\=63\times 10^{-14}\\\\\\=6.3\times 10^{-14+1}\\\\\\=6.3\times 10^{-13}$

                   Option: a is the answer.