Answer :

To find the perimeter of a rectangle, we use the formula:

[tex]\[ \text{Perimeter} = 2 \times (\text{Sum of the adjacent sides}) \][/tex]

Here, the adjacent sides are given by the expressions:

[tex]\[ \text{Side 1} = -6p^3 + 7p^2q^2 + pq \][/tex]

[tex]\[ \text{Side 2} = 7pq - 5p^3 + 9p^2q^2 \][/tex]

First, we need to find the sum of the adjacent sides:

[tex]\[ \text{Sum of the adjacent sides} = (\text{Side 1}) + (\text{Side 2}) \][/tex]

Let’s add the given expressions for the adjacent sides:

[tex]\[ \text{Sum} = (-6p^3 + 7p^2q^2 + pq) + (7pq - 5p^3 + 9p^2q^2) \][/tex]

Combine like terms in the expression:

[tex]\[ \text{Sum} = (-6p^3 - 5p^3) + (7p^2q^2 + 9p^2q^2) + (pq + 7pq) \][/tex]

Simplify each grouping:

[tex]\[ \text{Sum} = -11p^3 + 16p^2q^2 + 8pq \][/tex]

Therefore, the sum of the adjacent sides is:

[tex]\[ -11p^3 + 16p^2q^2 + 8pq \][/tex]

Next, to determine the perimeter, we multiply this sum by 2:

[tex]\[ \text{Perimeter} = 2 \times (-11p^3 + 16p^2q^2 + 8pq) \][/tex]

Distribute the 2:

[tex]\[ \text{Perimeter} = -22p^3 + 32p^2q^2 + 16pq \][/tex]

Hence, the perimeter of the rectangle is:

[tex]\[ -22p^3 + 32p^2q^2 + 16pq \][/tex]