91Ó°ÊÓ

Solve the given problems. Refer to Appendix B for units of measurement and their symbols. If \(a\) and \(b\) are positive integers and \(b>a,\) what type of number is represented by the following? (a) \(b-a\) (b) \(a-b\) (c) \(\frac{b-a}{b+a}\)

Set up an appropriate equation and solve. Data are accurate to two sig. digits unless greater accuracy is given. A car's radiator contains 12 L of antifreeze at a \(25 \%\) concentration. How many liters must be drained and then replaced by pure antifreeze to bring the concentration to \(50 \%\) (the manufacturer's "safe" level)?

Simplify the given expressions. In each of \(5-9\) and \(12-21,\) the result is an integer. $$\frac{7^{2} \sqrt{81}}{(-3)^{2} \sqrt{49}}$$

Simplify the given algebraic expressions. $$-2[-3(x-2 y)+4 y]$$

Simplify the given algebraic expressions. $$9 v-[6-(-v-4)+4 v]$$

Change numbers in ordinary notation to scientific notation or change numbers in scientific notation to ordinary notation. See Appendix \(B\) for an explanation of symbols used.The power plant at Grand Coulee Dam produces \(6,500,000 \mathrm{kW}\).

Change numbers in ordinary notation to scientific notation or change numbers in scientific notation to ordinary notation. See Appendix \(B\) for an explanation of symbols used.A certain computer has 60,000,000,000,000 bytes of memory.

Find the value of each square root by use of a calculator. Each number is approximate. $$\sqrt{85.4}$$

Simplify the given expressions. Express results with positive exponents only. $$\frac{x^{2} x^{3}}{\left(x^{2}\right)^{3}}$$

In Exercises \(5-48,\) simplify the given expressions. Express results with positive exponents only. $$\frac{\left(n^{2}\right)^{4}}{\left(n^{4}\right)^{2}}$$