Question

Perform the multiplication, (7x2+a2)(x2–3a2)

Answer 1

The given multiplied expression is

`(7x^2+a^2)(x^2-3a^2)=7x^4-20x^2a^2-3a^4`

Explanation:

Given expression is
`(7x^2+a^2)(x^2-3a^2)`

To find the multiplication of the given expression :

`(7x^2+a^2)(x^2-3a^2)`

By using the distributive property to solve the given expression as below

`(7x^2+a^2)(x^2-3a^2)=(7x^2)(x^2)+(7x^2)(-3a^2)+(a^2)(x^2)+(a^2)(-3a^2)`

`=7x^2.x^2-21x^2a^2+a^2x^2-3a^2.a^2`

`=7x^(2+2)-21x^2a^2+a^2x^2-3a^(2+2)` ( by using the property
`a^m.a^n=a^(m+n)` )

`=7x^4-21x^2a^2+a^2x^2-3a^4`

Adding the like terms in the above expression we get

`=7x^4-20x^2a^2-3a^4`

Therefore
`(7x^2+a^2)(x^2-3a^2)=7x^4-20x^2a^2-3a^4`

Therefore the given multiplied expression is

`(7x^2+a^2)(x^2-3a^2)=7x^4-20x^2a^2-3a^4`