Page 175 - ABCTE Study Guide_Neat

Generally, you will only be asked to do fairly simple problems on this topic; it's better suited for a
calculator than for mental math.

Question

Solve

A 5

B 15

C 25

D 41

Answer

The correct choice is A. 5 • 5 • 5 is 125. On problems like this, you can always work backwards from the
answer choices.

Fractional Powers

Fractional powers are very much like finding roots. Fractional powers require a bit of logical thinking, but,
for our purposes, we can examine some problems that only require some brainpower.

Briefly, here is the theory behind fractional powers. Let's look at it with the help of an example.

1/2
16 = x
1/2
1
1/2
16 • 16 = 16 1/2+1/2 = 16

Utilize the rule of multiplying powers with the same base.

1/2
Now go back and replace 16 with x.
1
x • x = 16
1/2
So x = 4, which means that 16 = 4. That is the same as the square root of 16.

1/2
How about 49 ?

You should have said 7.