How do you factor #r^3-8#?

2 Answers
May 21, 2018

#(r-2)(r^2 + 2r + 4)#

Explanation:

Difference of Cubes follows the formula:
#a^3 - b^3 = (a-b)(a^2 + ab + b^2)#

#r^3 - 8 = r^3 - 2^3 = (r-2)(r^2 + 2r + 4)#

May 21, 2018

#(r-2)(r^2+2r+4)#

Explanation:

#"this is a "color(blue)"difference of cubes"#

#"which factors in general as"#

#•color(white)(x)a^3-b^3=(a-b)(a^2+ab+b^2)#

#"here "a=r" and "b=2#

#rArrr^3-8=(r-2)(r^2+2r+4)#