Page 174 - ABCTE Study Guide_Neat
P. 174
9
B 12d
9
C 27d
10
D 81d
Answer
6
2 3
4
4
4 4
The correct answer is D. (3d) is equal to 3 d , or 81d . (d ) is equal to d because you multiply the
6
4
powers when you raise a power to a power. Then add the powers when you multiply 81d • d , to get
10
81d .
Roots
The opposite operation of raising a number to a power is to take its root. Square roots are the root with
which we are most familiar. Taking the square root is essentially removing the square from the number.
Example
2
6 = 36
2
(Technically, can also be (-6), since (-6) also equals 36.)
To find roots other than the square root, follow the same process. Without a calculator, you can really only
find perfect roots. You do this by working backwards and using mental math. To find the , you have to
think, some number times than same number equals 36. Algebraically, it would look like:
x • x = 36
For a cube root, it is the same, only there are three Xs instead of two.
Example
For higher numbered roots, the number of Xs is the same as the number of the root.
Example
