Supplementary Course Module C: Rational Expressions
Assignment 1 ° Simplifying Rational Expressions
Factoring:
°
A rational expression may be able to be simpli°ed if the numerator and denominator can be expressed as a
product of factors. Any factor that is common to both the numerator and denominator can be cancelled (similar
to how we ±reduced² fractions:
15
20
=
3
°
5
4
°
5
=
3
4
).
°
When we cancel, we are, in effect, dividing both the numerator and the denominator by the same factor ( i.e., we
can also think of
15
20
=
15
±
5
20
±
5
=
3
4
).
°
If the factor is an algebraic expression, we have to be careful that we are not dividing by a value equal to zero ³
recall that division by zero is not allowed!
°
a
b
=
ac
bc
,
c
6
= 0
and
ad
bd
=
a
b
,
d
6
= 0
°
any possible values which would result in division by zero are stated as restrictions, exempli°ed by the
following.
examples:
x
2
+
x
±
12
x
2
±
4
x
+ 3
=
(
x
+ 4) (
x
±
3)
(
x
±
1) (
x
±
3)
=
x
+ 4
x
±
1
, provided
x
6
= 3
12
x
2
y
±
9
x
3
y
4
+ 3
x
2
y
2
3
x
2
y
2
=
3
x
2
y
°
4
±
3
xy
3
+
y
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '10
 HU
 Algebra, Factoring, Rational Expressions, Factors, Fraction, Elementary arithmetic, Rational function, A+B A+B A+B

Click to edit the document details