Polynomials Review

Add the polynomials:

 $\left(5r-1\right)+\left(5r+7\right)$  

Add the polynomials:

 $\left(8x^2-4x-6\right)+\left(-5x^2+5x-6\right)$  

Subtract the polynomials:

 $\left(3x^2+4x\right)-\left(2x^2-x\right)$  

Subtract the polynomials:

 $\left(7n^2-n-4\right)-\left(2n^2+4n-7\right)$  

Multiply.

 $5y\left(3y-9\right)$  

Multiply.

 $\left(7n-7\right)\left(6n+3\right)$  

Multiply.

 $\left(4x-6\right)\left(4x+6\right)$  

Multiply.

 $\left(5n-6\right)^2$  

Multiply the polynomials.

 $\left(3x-3\right)\left(7x^2-7x+1\right)$  

The length and width of a rectangular pig pen are  $\left(6n+4\right)$  and  $\left(8n-4\right)$ . What is the area of the pig pen?