Perform the indicated operations. Indicate the degree of the resulting polynomial. $(7x^2-8xy+y^2)+(-8x^2-9xy-4y^2)$

Perform the indicated operations. Indicate the degree of the resulting polynomial. $(13x^3{y}^2-5x^{2}y-9x^2)-(-11x^3{y}^2-6x^{2}y+3x^2-4)$

Find each product. (x+7y)(3x-5y)

Find each product. $(a-b)(a^2+ab+b^2)$

Factor completely, or state that the polynomial is prime. $15x^3+3x^2$

Factor completely, or state that the polynomial is prime. $x^2-11x+28$

Factor and simplify each algebraic expression. $16x^{-\frac{3}{4}}+32x^{\frac{1}{4}}$

Factor and simplify each algebraic expression.$[12x^{-\frac{1}{2}}+6x^{-\frac{3}{2}}]$