91Ó°ÊÓ

In Exercises 1–4, is the algebraic expression a polynomial? If it is, write the polynomial in standard form. $$ 2 x+3 x^{2}-5 $$

find all numbers that must be excluded from the domain of each rational expression. $$ \frac{7}{x-3} $$

True or false. $$-13 \leq-2$$

Write each number in decimal notation without the use of exponents. $$ 3.8 \times 10^{2} $$

Write each number in scientific notation. $$ -5716 $$

Perform the indicated computations. Write the answers in scientific notation. If necessary, round the decimal factor in your scientific notation answer to two decimal places. $$ \left(8.2 \times 10^{8}\right)\left(4.6 \times 10^{4}\right) $$

Explaining the Concepts. Explain how to multiply two binomials using the FOIL. method. Give an example with your explanation.

Simplify each exponential expression. Assume that variables represent nonzero real numbers. $$ \frac{\left(x^{-2} y\right)^{-3}}{\left(x^{2} y^{-1}\right)^{3}} $$

In Exercises 111–113, perform the indicated operations. $$ [(7 x+5)+4 y][(7 x+5)-4 y] $$

Your local electronics store is having an end-of-the-year sale. The price on a plasma television had been reduced by 30%. Now the sale price is reduced by another 30%. If x is the television’s original price, the sale price can be modeled by original price, the sale price cafe $$(x-0.3 x)-0.3(x-0.3 x)$$