factoring 2

Agatha

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Mar 13, 2012
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can anybody help me with this? ab(a - b) - ac(a + c) + bc(2a + c - b)
i need to factor it :shock:
 
You could try expanding it out and try grouping appropriate terms.

\(\displaystyle a^{2}b-a^{2}c-ab^{2}+abc+abc-ac^{2}-b^{2}c+bc^{2}\)

Now, factor out a 'b':

\(\displaystyle b(a^{2}-ab+ac-bc)\)

Factor out a 'c':

\(\displaystyle c(a^{2}-ab+ac-bc)\)

See?. What's in the () is the same.

\(\displaystyle b(a^{2}-ab+ac-bc)-c(a^{2}-ab+ac-bc)\)

\(\displaystyle (b-c)(a^{2}-ab+ac-bc)\)

Now, factor what's in the parentheses and finish up
 
(bc)[a(a-b)+c(a-b)]=(b-c)(a-b)(a+c)!!!tkank you galactus!!!
sub.khan: obviously i couldn't otherwise you wouldn't see me post on this forum again.as you can see this polinomial is somewhat different,harder because you have to find greatre number of common monomials...and i got lazy since i found out this forum.
big thanks again galactus1
 
(bc)[a(a-b)+c(a-b)]=(b-c)(a-b)(a+c)!!!tkank you galactus!!!
sub.khan: obviously i couldn't otherwise you wouldn't see me post on this forum again.as you can see this polinomial is somewhat different,harder because you have to find greatre number of common monomials...and i got lazy since i found out this forum.
big thanks again galactus1

\(\displaystyle a^{2}b-a^{2}c-ab^{2}+abc+abc-ac^{2}-b^{2}c+bc^{2}\)

This is already set up as descending power of 'a' (as Soroban had suggested)

Now Factor out a2 and a (as Soroban had suggested)

\(\displaystyle a^{2}b-a^{2}c-ab^{2}+abc+abc-ac^{2}-b^{2}c+bc^{2}\)

\(\displaystyle = \ a^{2}(b-c) - ab(b-c) + ac(b-c) - bc(b-c)\)

\(\displaystyle = \ (b-c) [a^{2} - ab + ac - cb]\)

\(\displaystyle = \ (b-c) [a(a-b) + c(a - b)]\)

\(\displaystyle = \ (b-c)(a-b)(a+c)\)

It works EXACTLY like the problem before.......

I guess the operative sentence was

i got lazy
 
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