Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Solution to problem

long division problem

Hi, I'm correcting my work for study, and I cant get my head around this sum.

I understand where the $x^2 + x − cx$ comes from but then when the 6 appears it loses me.

share|improve this question
1  
$(x^2-5x+5cx-6b^2)-(x^2+x-cx)=x(-6+6c)-6b^2$ –  pedja Oct 9 '11 at 8:53
    
I dont understand shouldn't it be x(−5+5c)−6b^2 –  Rollo Oct 9 '11 at 9:20
    
Sorry, Sorry, I'm an idiot. –  Rollo Oct 9 '11 at 9:31
    
Did you try to solve left hand side of the equation that I wrote ? –  pedja Oct 9 '11 at 9:34

1 Answer 1

up vote 1 down vote accepted

$(x^2-5x+5cx-6b^2)-(x^2+x-cx)=x(-6+6c)-6b^2$

because:

$(x^2-5x+5cx-6b^2)-(x^2+x-cx) =$

(by distributing the - sign onto each operand in the bracket this is the equivelant of multilying each term by -1 so -(a+b-c)=-a-b+c)

$(x^2-5x+5cx-6b^2)-x^2 -x + cx =$

re-arranging the terms:

$x^2 - x^2 -x -5x+ cx + 5cx-6b^2 =$

$-6x+ 6cx - 6b^2 =$

$x(-6+6c)-6b^2$

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.