Easy Algebra Step-by-Step

Roots and Radicals 35

81 ≠± 9. The square root symbol

always gives just one nonnegative

number as the answer! If you want ± 9 ,

then do this: ±= 81 ± 9.

f. − 22 ⋅−

g. bb

Solution

a. 81

Step 1. Find the principal square root of 81.

81 = 9

b. 100

Step 1. Find the principal square root of 100.

100 = 10

c.

4

25

Step 1. Find the principal square root of

4

25

.

4

25

2

5

=

d.^30

Step 1. Find the principal square root of 30.

Because 30 is not a perfect square, 30 indicates the principal

square root of 30.

e.^916

Step 1. Add 9 and 16 because you want the principal square root of the

quantity 916. (See Chapter 5 for a discussion of as a grouping

symbol.)

911626 5

Step 2. Find the principal square root of 25.

911626 55

100 ≠ 50. You do not divide by

2 to get a square root.

91 +≠ 1669 + 16. 911626 55 ,

but 911636 + 474.