530 CHAPTER 8 Roots and Radicals
Students often have trouble distinguishing between the following two types of problems:
2316 t^2 - 2354 t^2 + 23128 t^2 A 1 + 233 BA 1 - 233 + 239 B
A^2107 -^2106 BA^2107 +^2106 B x^24 x^5 -^324 x^9 +x^224 x
B
3
16
81
275 x- 212 x A 5 + 323 B^2
26 - 25
26 + 25
- 4
234
8250
2225
623
B 5212
2
3 x
5
26 - 1
12
239
238 x^3 y^5 z^6
1
2 t + 23
A^23 +^6 BA^23 -^6 B
8
27 - 25
1 + 22
1 - 22
3
26
A^325 -^227 B
298 - 272 + 250 2
5210 - 8210 25 A 25 - 23 B A 1 + 23 BA 2 - 26 B
SUMMARY EXERCISESon Operations with Radicals
Simplifying a Radical Involving
a Square Root
Exercise: Simplify
Answer: 5
In this situation, represents the posi-
tive square root of 25, namely, 5.
Solving an Equation by Using
Square Roots
Exercise: Solve
Answer:
In this situation, has either of two
solutions: the negative square root of 25 or
the positive square root of 25—that is,
or 5. (See Exercise 36.)
- 5
x^2 = 25
5 - 5, 5 6
x^2 =25.
225
225.
Use the preceding information to work Exercises 26–35.
- (a)Simplify
(b)Solve
27. (a) Simplify
(b)Solve x^2 =81.
281.
x^2 =36.
236.
- (a)Solve
(b)Simplify
29. (a) Solve
(b)Simplify - 29.
x^2 =9.
x^2 =4.
- (a)Solve
(b)Simplify
31. (a) Solve
(b)Simplify 2491.
x^2 = 491.
2
1
4.
x^2 =^14.
- (a)Simplify
(b)Solve
33. (a) Simplify
(b)Solve x^2 = 10049.
- x^2 =^1625.
- (a)Solve
(b)Simplify
35. (a) Solve
(b)Simplify 2 0.16.
x^2 =0.16.
2 0.04.
x^2 =0.04.
36.Use the zero-factor property (Section 6.5)to show that the solution set of is
5 - 5, 5 6.
x^2 = 25
Perform all indicated operations and express each answer in simplest form. Assume that all
variables represent positive numbers.
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