Chapter 1

Intermediate Algebra · 580 exercises

Problem 84

Chemistry. The pH scale is used to measure the strength of acids and bases (alkalines). It can be thought of as a number line. On the scale, graph and label each pH measurement given below. $$ \begin{array}{|l|r|} \hline \text { Solution } & \mathrm{pH} \\ \hline \text { Seawater } & 8.5 \\ \hline \text { Cola } & 2.9 \\ \hline \text { Battery acid } & 1.0 \\ \hline \text { Milk } & 6.6 \\ \hline \text { Blood } & 7.4 \\ \hline \text { Ammonia } & 11.9 \\ \hline \text { Saliva } & 6.1 \\ \hline \text { Oven cleaner } & 13.2 \\ \hline \text { Black coffee } & 5.0 \\ \hline \text { Toothpaste } & 9.9 \\ \hline \text { Tomato juice } & 4.1 \\ \hline \end{array} $$

3 step solution

Problem 85

Simplify. See Example \(6 .\) $$24\left(\frac{5}{6} y-\frac{9}{8}\right)-24\left(\frac{3}{24} y\right)$$

3 step solution

Problem 85

Solve each equation. $$ -(2 t-0.71)=0.9(1.4-t) $$

5 step solution

Problem 85

Solve for the specified variable. $$ d=\frac{4}{3} \pi h \quad \text { for } h $$

4 step solution

Problem 85

Evaluate each expression. See Example \(9 .\) $$ \frac{-2-5}{-7+(-7)} $$

3 step solution

Problem 86

Simplify. See Example \(6 .\) $$18\left(\frac{11}{18} w-\frac{7}{2}\right)-18\left(\frac{1}{9} w\right)$$

3 step solution

Problem 86

Solve each equation. $$ -(9 m-11.13)=7.7(6+m) $$

5 step solution

Problem 86

Solve for the specified variable. $$ I_{Q}=\frac{100 M}{C} \text { for } C $$

3 step solution

Problem 86

Evaluate each expression. See Example \(9 .\) $$ \frac{-3-(-1)}{-2+(-2)} $$

3 step solution

Problem 87

Solve each equation. $$ 2(2 x+1)=x+15+2 x $$

4 step solution

Problem 87

Evaluate each expression. See Example \(9 .\) $$ \frac{|-25|-2(-5)}{2^{4}-9} $$

4 step solution

Problem 87

Explain why the whole numbers are a subset of the integers.

4 step solution

Problem 88

Simplify. See Example \(6 .\) $$-5[3(x-4)-2(x+2)]-7(x-3)$$

6 step solution

Problem 88

Solve each equation. $$ -2(x+5)=x+30-2 x $$

5 step solution

Problem 88

Aluminum Foil. Find the number of square feet of aluminum foil on a roll if the dimensions printed on the box are \(8 \frac{1}{3}\) yards \(\times 12\) inches.

3 step solution

Problem 88

Evaluate each expression. See Example \(9 .\) $$ \frac{2[-4-2(3-1)]}{3(3)(2)} $$

5 step solution

Problem 88

What is a real number? Give examples.

3 step solution

Problem 89

Simplify. See Example \(6 .\) $$2\left[6\left(\frac{1}{3} a+2 b\right)-8\left(\frac{1}{4} a-2 b\right)+3\right]$$

4 step solution

Problem 89

Solve each equation. $$ \frac{5}{2} a-12=\frac{1}{3} a+1 $$

5 step solution

Problem 89

Evaluate each expression. See Example \(9 .\) $$ \frac{3[-9+2(7-3)]}{(8-5)(9-7)} $$

5 step solution

Problem 89

Explain why there are no even prime numbers greater than 2 .

5 step solution

Problem 90

Simplify. See Example \(6 .\) $$10\left[\frac{3}{5}(2 s+2 t)-\frac{4}{5}(s-t)+1\right]$$

4 step solution

Problem 90

Solve each equation. $$ 3(x-2)+4=3 x-2 $$

4 step solution

Problem 90

Hockey. A goal is scored in hockey when the puck, a vulcanized rubber disk \(2.5 \mathrm{cm}(1 \text { in. ) thick and } 7.6 \mathrm{cm}(3 \mathrm{in.})\) in diameter, is driven into the opponent's goal. Find the volume of a puck in cubic centimeters and cubic inches. Round to the nearest tenth.

5 step solution

Problem 90

Evaluate each expression. See Example \(9 .\) $$ \frac{(6-5)^{4}+21}{27-(\sqrt{16})^{2}} $$

3 step solution

Problem 90

Explain why every integer is a rational number, but not every rational number is an integer.

4 step solution

Problem 91

Simplify each expression. $$-(a+2 A+1)-(a-A+2)$$

2 step solution

Problem 91

Solve each equation. $$ \frac{4}{5} a=-12 $$

4 step solution

Problem 91

Is \(\frac{3 x-4}{2}\) an equation or an expression?

3 step solution

Problem 92

Simplify each expression. $$3 T-2(t-T)+t$$

3 step solution

Problem 92

Solve each equation. $$ 4 j+12.54=18.12 $$

3 step solution

Problem 92

Translate into mathematical symbols: The weight of an object in ounces is the product of 16 and its weight in pounds.

4 step solution

Problem 93

Simplify each expression. $$8(2 c d+7 c)-2(c d-3 c)$$

3 step solution

Problem 93

Solve each equation. $$ 0.06(a+200)+0.1 a=172 $$

5 step solution

Problem 93

Fill in the blank: A ____ is a letter that stands for a number.

4 step solution

Problem 94

Simplify each expression. $$2 t z+5(t z-4)-10(8-t z)$$

2 step solution

Problem 94

Solve each equation. $$ 0.03 x+0.05(6,000-x)=280 $$

4 step solution

Problem 94

Electronics. The illustration below is a diagram of a resistor connected to a voltage source of 60 volts. As a result, the resistor loses power in the form of heat. The power \(P\) lost when a voltage \(E\) is placed across a resistance \(R\) (in ohms) is given by the formula $$ P=\frac{E^{2}}{R} $$ Solve for \(R\). If \(P\) is 4.8 watts and \(E\) is 60 volts, find \(R\). (IMAGE CANT COPY)

4 step solution

Problem 94

Complete the table. $$ T=x-1.5 $$ $$ \begin{array}{|c|c|} \hline x & T \\ \hline 3.7 & \\ \hline 10 & \\ \hline \end{array} $$

3 step solution

Problem 95

Simplify each expression. $$6.4 a^{2}+11.8 a-9.2 a+5.7$$

3 step solution

Problem 95

Solve each equation. $$ -4[p-(3-p)]=3(6 p-2) $$

5 step solution

Problem 95

How many integers have an absolute value that is less than \(1,000 ?\)

4 step solution

Problem 96

Simplify each expression. $$9.1 m^{2}-6.1 m+12.3 m-4.9$$

3 step solution

Problem 96

Solve each equation. $$ 2[5(4-a)+2(a-1)]=3-a $$

5 step solution

Problem 96

Investments. An amount \(P\), invested at a simple interest rate \(r\) will grow to an amount \(A\) in \(t\) years according to the formula \(A=P(1+r t) .\) Solve for \(P .\) Suppose a man invested some money at \(5.5 \%\). If after 5 years, he had \(\$ 6,693.75\) on deposit, what amount did he originally invest?

7 step solution

Problem 96

Find a fraction whose decimal equivalent is \(0 . \overline{61}\)

5 step solution

Problem 97

Simplify each expression. $$-\frac{7}{16} x-\frac{3}{4} x$$

5 step solution

Problem 97

Solve each equation. $$ 2(x-2)=\frac{2}{3}(3 x+8)-2 $$

4 step solution

Problem 97

Cost of Electricity. The cost of electricity in a city is given by the formula \(C=0.07 n+6.50,\) where \(C\) is the cost in dollars and \(n\) is the number of kilowatt hours used. Solve for \(n .\) Then find the number of kilowatt hours used each month by a homeowner whose checks to pay the monthly clectric bills are: \(\$ 49.97, \$ 76.50,\) and \(\$ 125\)

6 step solution

Problem 97

The trichotomy property of real numbers states that if \(a\) and \(b\) are real numbers, then \(ab .\) Explain why this is true.

5 step solution

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