Question

Find the product (3a4+4)2​

Answer 1

The result is

9

a

2

−

16

The reason is the following:

The problem is an example of a notable product: "the sum multiplied by the diference is equal to the difference of squares", that is to say:

(

a

+

b

)

⋅

(

a

−

b

)

=

a

2

−

b

2

.

By applying this to our question, we obtain that:

(

3

a

−

4

)

⋅

(

3

a

+

4

)

=

(

3

a

)

2

−

(

4

)

2

=

9

a

2

−

16

.

Answer 2

The product is 9a^8+24a^4+16

Explanation:

Since we have given that (3a^4+4)^2

As we know that (a+b)^2=a^2+2ab+b^2

So, it becomes, (3a^4 + 4)^2=(3a^4)^2+2\times 3a^4\times 4+(4)^2\\\\=9a^8+24a^4+16

Hence, the product is 9a^8+24a^4+16