Use the identity below to complete the tasks:

[tex]\[a^3 - b^3 = (a - b)(a^2 + ab + b^2)\][/tex]

When using the identity for the sum of two cubes to factor [tex]\(125a^6 - r^6s^3\)[/tex]:

What is [tex]\(a\)[/tex]? [tex]\(\square\)[/tex]
What is [tex]\(b\)[/tex]? [tex]\(\square\)[/tex]



Answer :

To factor the expression [tex]\(125 a^6 - r^6 s^3\)[/tex] using the sum of cubes identity, we first need to express [tex]\(125 a^6\)[/tex] and [tex]\(r^6 s^3\)[/tex] in terms of cubes.

The identity for the difference of two cubes is:
[tex]\[ a^3 - b^3 = (a - b)(a^2 + ab + b^2) \][/tex]

Let's identify the terms in the form of [tex]\(A^3\)[/tex] and [tex]\(B^3\)[/tex]:

1. Identify [tex]\(a^3\)[/tex] in the term [tex]\(125 a^6\)[/tex]:
[tex]\[ 125 a^6 = (5a^2)^3 \][/tex]
Here, [tex]\(a = 5a^2\)[/tex].

2. Identify [tex]\(b^3\)[/tex] in the term [tex]\(r^6 s^3\)[/tex]:
[tex]\[ r^6 s^3 = (r^2 s)^3 \][/tex]
Here, [tex]\(b = r^2 s\)[/tex].

Now, substituting these back into the identity:
[tex]\[ a^3 - b^3 = (a - b)(a^2 + ab + b^2) \][/tex]

In our case:
[tex]\[ (5a^2)^3 - (r^2 s)^3 \][/tex]

Thus, we have:
[tex]\[ A = 5a^2 \quad \text{and} \quad B = r^2 s \][/tex]

So, the values are:
[tex]\[ a = 5a^2 \quad \text{and} \quad b = r^2 s \][/tex]