Question 440060
y cube root(56x) - cube root(189 x y^3)
y cube root(8*7x) - cube root(27*7 x y^3)
y cube root(2^3*7x) - cube root(3^3*7 x y^3)
pull out 2^3, 3^3 & y^3
2y cube root(7x) -3y cube root(7x)
-y cube root(7x) (ans)