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TWO
TERMS: DIFFERENCE OF SQUARES
TO
BE FACTORABLE AN EXPRESSION WITH TWO TERMS MUST BE ONE OF THE FOLLOWING:
-
PERFECT
SQUARE - PERFECT SQUARE
-
PERFECT
CUBE - PERFECT CUBE
-
PERFECT
CUBE + PERFECT CUBE
In
this course, we only deal with the difference between two squares.
Recognizing
terms that are perfect squares
Numbers:
The
square root of the number must be rational. The square root will
be a whole number, a fraction,or a decimal that is repeating or terminating.
Letters
with exponents: The exponent of the letter
must be even.
Letters
and numbers: Both must be perfect squares.
64
is a perfect square since it's square root is 8.
1/4
is a perfect square since it's square root is 1/2.
x8
is a perfect square since 8 is even.
x9
is not a perfect square since 9 is not even.
9x4
is a perfect square. (It's square root is 3x2)
3x2
is not a perfect square since 3 is not a perfect square.
Factoring
the difference of two squares
If
an expression is of the form perfect square
- perfect square it will factor into two binomials
that have the same terms but opposite signs between them.
To
factor A2 - B2 the two
binomials would be (A - B)(A + B)
The
pattern will be the same for any perfect square minus perect square with
the first positions being the square root of the first term and the second
positions being the square root of the second term.
To
factor 4x2 - 9y2 we
will get (2x - 3y)(2x + 3y)
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