91Ó°ÊÓ

Convert each number into scientific notation. $$56 \times 10^{-2}$$

Simplify each of the following as completely as possible. $$\left(2 x y^{2}\right)^{3}$$

Simplify each of the following expressions as completely as possible. Final answers should be expressed with positive exponents only. (Assume that all variables represent positive quantities.) $$a^{5} a^{-2}$$

Convert each number into scientific notation. $$872 \times 10^{5}$$

Multiply out each of the following. As you work out the problems, identify those exercises that are either a perfect square or the difference of two squares. $$(t-6)(t-6)$$

In Exercises \(27-50,\) perform the indicated operations and simplify. $$\left(5 w^{4}-w^{3}-w\right)+\left(2 w^{3}-3 w^{2}-5 w\right)$$

Multiply and simplify each of the following. Whenever possible, do the multiplication of two binomials mentally. $$(2 c-1)\left(6 c^{2}-3 c-1\right)$$

In Exercises \(27-50,\) perform the indicated operations and simplify. $$\left(3 u^{3}-2 u+7\right)-\left(u^{3}-u^{2}+7 u\right)$$

Simplify each of the following expressions as completely as possible. Final answers should be expressed with positive exponents only. (Assume that all variables represent positive quantities.)$$a^{2} a^{-4} a a^{-7}$$

Multiply and simplify each of the following. Whenever possible, do the multiplication of two binomials mentally. $$(x+y)\left(x^{2}-x y+y^{2}\right)$$