Chapter 2

Algebra and Trigonometry Real Mathematics, Real People · 560 exercises

Problem 27

Find all solutions of the equation algebraically. Check your solutions. $$\sqrt{x+1}-3 x=1$$

6 step solution

Problem 27

Solve the equation by extracting square roots. List both the exact solutions and the decimal solutions rounded to the nearest hundredth. $$(x-12)^{2}=16$$

3 step solution

Problem 27

Solve the equation algebraically. Then write the equation in the form \(f(x)=0\) and use a graphing utility to verify the algebraic solution. $$2.7 x-0.4 x=1.2$$

5 step solution

Problem 27

Perform the addition or subtraction and write the result in standard form. $$(1.6+3.2 i)+(-5.8+4.3 i)$$

4 step solution

Problem 27

Solve the equation (if possible). $$\frac{x}{5}-\frac{x}{2}=3$$

2 step solution

Problem 28

In a study, 60 colts were measured every 14 days from birth. The ordered pairs \((d, l)\) represent the average length \(l\) (in centimeters) of the 60 colts \(d\) days after birth. (Spreadsheet at LarsonPrecalculus.com) $$\begin{aligned} &(14,81.2)\\\ &(56,98.3)\\\ &(98,110.0) \end{aligned}$$ $$\begin{aligned} &(28,87.1)\\\ &(70,102.4) \end{aligned}$$ $$\begin{aligned} &(42,93.7)\\\ &(84,106.2) \end{aligned}$$ (a) Use the regression feature of a graphing utility to find a linear model for the data and to identify the correlation coefficient. (b) According to the correlation coefficient, does the model represent the data well? Explain. (c) Use the graphing utility to plot the data and graph the model in the same viewing window. How closely does the model fit the data? (d) Use the model to predict the average length of a colt 112 days after birth.

4 step solution

Problem 28

Solve the inequality and sketch the solution on the real number line. Use a graphing utility to verify your solution graphically. $$0 \leq 2-3(x+1)<20$$

6 step solution

Problem 28

Find all solutions of the equation algebraically. Check your solutions. $$\sqrt{x+5}-2 x=3$$

5 step solution

Problem 28

Solve the equation by extracting square roots. List both the exact solutions and the decimal solutions rounded to the nearest hundredth. $$(x-5)^{2}=25$$

3 step solution

Problem 28

Solve the equation algebraically. Then write the equation in the form \(f(x)=0\) and use a graphing utility to verify the algebraic solution. $$3.6 x-8.2=0.5 x$$

5 step solution

Problem 28

Perform the addition or subtraction and write the result in standard form. $$-(-3.7-12.8 i)-(6.1-16.3 i)$$

3 step solution

Problem 28

Solve the equation (if possible). $$\frac{3 x}{4}+\frac{x}{2}=-5$$

3 step solution

Problem 29

Determine whether the statement is true or false. Justify your answer. A linear regression model with a positive correlation will have a slope that is greater than \(0 .\)

3 step solution

Problem 29

Solve the inequality and sketch the solution on the real number line. Use a graphing utility to verify your solution graphically. $$-4<\frac{2 x-3}{3}<4$$

5 step solution

Problem 29

Find all solutions of the equation algebraically. Check your solutions. $$\sqrt{x+1}=\sqrt{3 x+1}$$

5 step solution

Problem 29

Solve the equation by extracting square roots. List both the exact solutions and the decimal solutions rounded to the nearest hundredth. $$(3 x-1)^{2}+6=0$$

4 step solution

Problem 29

Solve the equation algebraically. Then write the equation in the form \(f(x)=0\) and use a graphing utility to verify the algebraic solution. $$12(x+2)=15(x-4)-3$$

4 step solution

Problem 29

Perform the addition or subtraction and write the result in standard form. $$(5+\sqrt{-27})-(-12+\sqrt{-48})$$

3 step solution

Problem 29

Solve the equation (if possible). $$\frac{5 x-4}{5 x+4}=\frac{2}{3}$$

4 step solution

Problem 30

Solve the inequality and sketch the solution on the real number line. Use a graphing utility to verify your solution graphically. $$0 \leq \frac{x+3}{2}<5$$

4 step solution

Problem 30

Find all solutions of the equation algebraically. Check your solutions. $$\sqrt{x+5}=\sqrt{2 x-5}$$

4 step solution

Problem 30

Solve the equation by extracting square roots. List both the exact solutions and the decimal solutions rounded to the nearest hundredth. $$(2 x+3)^{2}+25=0$$

3 step solution

Problem 30

Solve the equation algebraically. Then write the equation in the form \(f(x)=0\) and use a graphing utility to verify the algebraic solution. $$1200=300+2(x-500)$$

3 step solution

Problem 30

Perform the addition or subtraction and write the result in standard form. $$(7+\sqrt{-18})+(3+\sqrt{-32})$$

3 step solution

Problem 30

Solve the equation (if possible). $$\frac{10 x+3}{5 x+6}=\frac{1}{2}$$

3 step solution

Problem 31

Use your school's library, the Internet, or some other reference source to locate data that you think describe a linear relationship. Create a scatter plot of the data and find the least squares regression line that represents the points. Interpret the slope and \(y\) -intercept in the context of the data. Write a summary of your findings.

5 step solution

Problem 31

Use a graphing utility to approximate the solution. $$5-2 x \geq 1$$

4 step solution

Problem 31

Find all solutions of the equation algebraically. Check your solutions. $$2 x+9 \sqrt{x}-5=0$$

6 step solution

Problem 31

Solve the equation by extracting square roots. List both the exact solutions and the decimal solutions rounded to the nearest hundredth. $$(x-7)^{2}=(x+3)^{2}$$

4 step solution

Problem 31

Solve the equation algebraically. Then write the equation in the form \(f(x)=0\) and use a graphing utility to verify the algebraic solution. $$\frac{3 x}{2}+\frac{1}{4}(x+2)=10$$

4 step solution

Problem 31

Perform the operation and write the result in standard form. $$\sqrt{-6} \cdot \sqrt{-2}$$

3 step solution

Problem 31

Solve the equation (if possible). $$\frac{2}{5}(z-4)+\frac{3 z}{10}=4 z$$

3 step solution

Problem 32

Find all solutions of the equation algebraically. Check your solutions. $$6 x-7 \sqrt{x}-3=0$$

5 step solution

Problem 32

Solve the equation by extracting square roots. List both the exact solutions and the decimal solutions rounded to the nearest hundredth. $$(x+5)^{2}=(x+4)^{2}$$

4 step solution

Problem 32

Solve the equation algebraically. Then write the equation in the form \(f(x)=0\) and use a graphing utility to verify the algebraic solution. $$\frac{2 x}{3}+\frac{1}{2}(x-5)=6$$

5 step solution

Problem 32

Perform the operation and write the result in standard form. $$\sqrt{-5} \cdot \sqrt{-10}$$

3 step solution

Problem 32

Solve the equation (if possible). $$\frac{3 x}{2}+\frac{1}{4}(x-2)=10$$

4 step solution

Problem 33

Evaluate the function at each value of the independent variable and simplify. \(f(x)=2 x^{2}-3 x+5\) (a) \(f(-1)\) (b) \(f(w+2)\)

4 step solution

Problem 33

Use a graphing utility to approximate the solution. $$3(x+1)

4 step solution

Problem 33

Find all solutions of the equation algebraically. Check your solutions. $$\sqrt{x}-\sqrt{x-5}=1$$

6 step solution

Problem 33

Solve the quadratic equation by completing the square. Verify your answer graphically. $$x^{2}+4 x-32=0$$

5 step solution

Problem 33

Solve the equation algebraically. Then write the equation in the form \(f(x)=0\) and use a graphing utility to verify the algebraic solution. $$0.60 x+0.40(100-x)=1.2$$

4 step solution

Problem 33

Perform the operation and write the result in standard form. $$(\sqrt{-10})^{2}$$

3 step solution

Problem 33

Solve the equation (if possible). $$\frac{17+y}{y}+\frac{32+y}{y}=100$$

3 step solution

Problem 34

Evaluate the function at each value of the independent variable and simplify. \(g(x)=5 x^{2}-6 x+1\) (a) \(g(-2)\) (b) \(g(z-2)\)

2 step solution

Problem 34

Use a graphing utility to approximate the solution. $$4(x-3)>8-x$$

4 step solution

Problem 34

Find all solutions of the equation algebraically. Check your solutions. $$\sqrt{x}+\sqrt{x-20}=10$$

5 step solution

Problem 34

Solve the quadratic equation by completing the square. Verify your answer graphically. $$x^{2}-2 x-3=0$$

5 step solution

Problem 34

Solve the equation algebraically. Then write the equation in the form \(f(x)=0\) and use a graphing utility to verify the algebraic solution. $$0.75 x+0.2(80-x)=3.9$$

6 step solution

Problem 34

Perform the operation and write the result in standard form. $$(\sqrt{-75})^{2}$$

3 step solution

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