Question

Not understanding how to work sum of cubes 125x^3+27y^3

Answer 1

do u need to factor them

Answer 2

then use a^3+b^3= (a+b)(a^2 -ab+b^2)

Answer 3

for a^3-b^3= (a-b)(a^2 +ab+b^2)

Answer 4

\[ 125x^3+27y^3 = (5x)^3 + (3y)^3\]

Answer 5

if u need not factor them then use
a^3+b^3 =(a+b)^3 -3ab(a+b)

Answer 6

Now a = 5x and b =3y.

Answer 7

125x^3+27y^3 =(5x)^3 +(3y)^3
=(5x+3y)(25x^2 -15xy +9y^2)