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Feb. 23/17
A binomial can
be a common factor!
1
12x2 + 48x =
b(3x)
2
(x 2)
2(12x2 + 48x) = (3x)b
24x2 + 96x = (3x)b
2
(common
factor
the left side)
24x
+ 96x
= (3x)b
24x(x + 4) = (3x)b
(÷ 3x)
824x(x
+ 4) = (3x)b
3x
3x
8(x + 4) = b
the base is 8(x + 4) or 8x + 32.
Ex. 3 Show that 3 - x is a common factor of 2(x - 3) + 5x(x - 3).
2(x - 3) + 5x(x - 3)
common factor -I
from each x-3.
= 2[-(-x + 3)] + 5x[-(-x + 3)]
= -2(3 - x) -5x(3 - x)
= (3 - x)(-2 - 5x)
= -6 - 15x + 2x + 5x2
= 5x - 13x - 6
2
Check original expression.
2( x - 3) + 5x(x - 3)
= 2x - 6 + 5x2 - 15x
= 5x2 - 13x - 6
2