Simplify [tex]\frac{m+\left(m n^2\right)^3+\left(m^2 n\right)^3}{m-n} \times\left(1-\frac{n^3}{m^3}\right)[/tex].



Answer :

To simplify the given expression:

[tex]\[ \frac{m + \left(m n^2\right)^3 + \left(m^2 n\right)^3}{m-n} \times \left(1 - \frac{n^3}{m^3}\right) \][/tex]

we proceed step-by-step.

### Step 1: Simplify the numerator

The expression within the numerator is:

[tex]\[ m + (m n^2)^3 + (m^2 n)^3 \][/tex]

Rewrite the terms individually:

[tex]\[ (m n^2)^3 = m^3 n^6 \][/tex]
[tex]\[ (m^2 n)^3 = m^6 n^3 \][/tex]

Hence, the numerator becomes:

[tex]\[ m + m^3 n^6 + m^6 n^3 \][/tex]

### Step 2: Simplify the entire fraction

The fraction we are dealing with is:

[tex]\[ \frac{m + m^3 n^6 + m^6 n^3}{m - n} \][/tex]

### Step 3: Consider the second part of the expression separately

The second part of the expression is:

[tex]\[ 1 - \frac{n^3}{m^3} \][/tex]

This can be rewritten as:

[tex]\[ \frac{m^3 - n^3}{m^3} \][/tex]

### Step 4: Combine the two parts

Now, multiply the simplified fraction by the simplified second part:

[tex]\[ \left( \frac{m + m^3 n^6 + m^6 n^3}{m - n} \right) \times \left( \frac{m^3 - n^3}{m^3} \right) \][/tex]

### Step 5: Use polynomial identities

Recall that [tex]\( m^3 - n^3 \)[/tex] can be factored as:

[tex]\[ m^3 - n^3 = (m - n)(m^2 + mn + n^2) \][/tex]

So the expression becomes:

[tex]\[ \frac{m + m^3 n^6 + m^6 n^3}{m - n} \times \frac{(m - n)(m^2 + mn + n^2)}{m^3} \][/tex]

### Step 6: Cancel common terms

Observe that [tex]\( m - n \)[/tex] appears in both the numerator and the denominator and can be canceled out. This yields:

[tex]\[ \frac{m + m^3 n^6 + m^6 n^3}{1} \times \frac{m^2 + mn + n^2}{m^3} \][/tex]

### Step 7: Distribute and simplify the remaining expression

Let's multiply out the terms:

[tex]\[ \big(m + m^3 n^6 + m^6 n^3\big) \times \frac{(m^2 + mn + n^2)}{m^3} \][/tex]

Distribute each part of the first expression through the second fraction:

[tex]\[ \left(\frac{m (m^2 + mn + n^2)}{m^3}\right) + \left(\frac{m^3 n^6 (m^2 + mn + n^2)}{m^3}\right) + \left(\frac{m^6 n^3 (m^2 + mn + n^2)}{m^3}\right) \][/tex]

This simplifies to:

[tex]\[ \frac{m^3 + m^2 mn + mn^2}{m^3} + \frac{m^2 n^6 + mn^7 + n^8}{1} + \frac{m^5 n^3 + m^4 n^4 + m^3 n^5}{m} \][/tex]

### Step 8: Combine like terms

This will further simplify and combine like terms to eventually yield:

[tex]\[ \frac{(m^3 - n^3)(m^5 n^3 + m^2 n^6 + 1)}{m^2 (m - n)} \][/tex]

Thus, the final simplified form of the expression is:

[tex]\[ \boxed{\frac{(m^3 - n^3)(m^5 n^3 + m^2 n^6 + 1)}{m^2 (m - n)}} \][/tex]