How do you factor 9x^3-x?
3 Answers
Explanation:
Jan 25, 2017
Explanation:
Jan 25, 2017
Explanation:
There is a
color(blue)"common factor" of x in both terms.
rArrx(9x^2-1)larrcolor(red)"remove common factor"
9x^2-1" is a"color(blue)" difference of squares" and factorises, in general as shown.
color(red)(bar(ul(|color(white)(2/2)color(black)(a^2-b^2=(a-b)(a+b))color(white)(2/2)|)))
"here " (3x)^2=9x^2" and " 1^2=1
rArra=3x" and " b=1
rArr9x^2-1=(3x-1)(3x+1)
rArr9x^3-1=x(3x-1)(3x+1)larrcolor(red)" fully factorised"