91Ó°ÊÓ

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.) $$-(3 y)^{-2}$$

Multiply and simplify each of the following. Whenever possible, do the multiplication of two binomials mentally. $$(a+8 b)(a-5 b)$$

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.)$$x y^{-1}$$

Convert each number into standard notation. $$0.026 \times 10^{-3}$$

Simplify each of the following as completely as possible. $$\left(\frac{2 x^{3} y^{4}}{x y^{6}}\right)^{5}$$

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. $$(3 x+4)(x-7)$$

Convert each number into standard notation. $$78,951 \times 10^{-5}$$

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. $$(2 y+5)(y-3)$$

In Exercises \(27-50,\) perform the indicated operations and simplify. Subtract \(m^{4}-m^{3} p-5 p\) from the sum of \(2 m^{3} p-p\) and \(4 m^{4}-5 p+6\)

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.) $$(x y)^{-1}$$