1. In a radical equation, what does it mean if a number is an extraneous solution?
2. Explain why possible solutions must be checked in radical equations.
3. Your friend tries to calculate the value −932−932 and keeps getting an ERROR message. What mistake is he or she probably making?
4. Explain why |2x+5|=−7|2x+5|=−7 has no solutions.
5. Explain how to change a rational exponent into the correct radical expression.
For the following exercises, solve the rational exponent equation. Use factoring where necessary.
6. x23=16x23=16
7. x34=27x34=27
8. 2x12−x14=02x12−x14=0
9. (x−1)34=8(x−1)34=8
10. (x+1)23=4(x+1)23=4
11. x23−5x13+6=0x23−5x13+6=0
12. x73−3x43−4x13=0x73−3x43−4x13=0
For the following exercises, solve the following polynomial equations by grouping and factoring.
13. x3+2x2−x−2=0x3+2x2−x−2=0
14. 3x3−6x2−27x+54=03x3−6x2−27x+54=0
15. 4y3−9y=04y3−9y=0
16. x3+3x2−25x−75=0x3+3x2−25x−75=0
17. m3+m2−m−1=0m3+m2−m−1=0
18. 2x5−14x3=02x5−14x3=0
19. 5x3+45x=2x2+185x3+45x=2x2+18
For the following exercises, solve the radical equation. Be sure to check all solutions to eliminate extraneous solutions.
20. √3x−1−2=0√3x−1−2=0
21. √x−7=5√x−7=5
22. √x−1=x−7√x−1=x−7
23. √3t+5=7√3t+5=7
24. √t+1+9=7√t+1+9=7
25. √12−x=x√12−x=x
26. √2x+3−√x+2=2√2x+3−√x+2=2
27. √3x+7+√x+2=1√3x+7+√x+2=1
28. √2x+3−√x+1=1√2x+3−√x+1=1
For the following exercises, solve the equation involving absolute value.
29. |3x−4|=8|3x−4|=8
30. |2x−3|=−2|2x−3|=−2
31. |1−4x|−1=5|1−4x|−1=5
32. |4x+1|−3=6|4x+1|−3=6
33. |2x−1|−7=−2|2x−1|−7=−2
34. |2x+1|−2=−3|2x+1|−2=−3
35. |x+5|=0|x+5|=0
36. −|2x+1|=−3−|2x+1|=−3
For the following exercises, solve the equation by identifying the quadratic form. Use a substitute variable and find all real solutions by factoring.
37. x4−10x2+9=0x4−10x2+9=0
38. 4(t−1)2−9(t−1)=−24(t−1)2−9(t−1)=−2
39. (x2−1)2+(x2−1)−12=0(x2−1)2+(x2−1)−12=0
40. (x+1)2−8(x+1)−9=0(x+1)2−8(x+1)−9=0
41. (x−3)2−4=0(x−3)2−4=0
For the following exercises, solve for the unknown variable.
42. x−2−x−1−12=0x−2−x−1−12=0
43. √|x|2=x√|x|2=x
44. t25−t5+1=0t25−t5+1=0
45. |x2+2x−36|=12|x2+2x−36|=12
For the following exercises, use the model for the period of a pendulum, TT, such that T=2π√LgT=2π√Lg, where the length of the pendulum is L and the acceleration due to gravity is gg.
46. If the acceleration due to gravity is 9.8m/s29.8m/s2 and the period equals 1 s, find the length to the nearest cm (100 cm = 1 m).
47. If the gravity is 32fts232fts2 and the period equals 1 s, find the length to the nearest in. (12 in. = 1 ft). Round your answer to the nearest in.
For the following exercises, use a model for body surface area, BSA, such that BSA=√wh3600BSA=√wh3600, where w = weight in kg and h = height in cm.
48. Find the height of a 72-kg female to the nearest cm whose BSA=1.8BSA=1.8.
49. Find the weight of a 177-cm male to the nearest kg whose BSA=2.1BSA=2.1.
Candela Citations
- College Algebra. Authored by: OpenStax College Algebra. Provided by: OpenStax. Located at: http://cnx.org/contents/9b08c294-057f-4201-9f48-5d6ad992740d@3.278:1/Preface. License: CC BY: Attribution