Idiot\'s Guides Basic Math and Pre-Algebra

108 Part 2: Into the Unknown

The toughest problems are the ones in which there is addition or subtraction in the denominator.

Unfortunately, they’re not as easy to break into smaller problems. If you go back to regular

fractions for a minute, remember that

5

23 

does not equal^5

2

5

3

.

There are ways to do division problems like xx

x

(^256)
3


, but you’ll need more experience with
different algebra tools before you’re ready for them. For now, practice with division problems in
which the denominator does not include addition or subtraction. Reduce fractions, use the laws
of exponents, and don’t forget to always add the note that says your denominator can’t be zero.
CHECK POINT
Write each quotient in simplest form.

11.^14
7

• t

12.^11

3

2

a

a

, a { 0

13.^18
6

4

3

x

x

, x { 0

14.^42

14

7

4

y

y

, y { 0

15.^127232
4

xx x^32

x

 , x { 0

The Least You Need to Know

• Variables are letters or symbols that represent unknown numbers.


• Multiply numbers with numbers and variables with variables.


• When multiplying the same variable many times, use an exponent.


• To divide an expression by a variable, make separate fractions and reduce.


• You cannot divide another number by zero.