立方根求x8x3+125=08(x+5)3
求x 8x3+125=0 8(x+5)3-27=0
8x^3+125=0 x^3=-125/8 x=-5/2 8(x+5)^3-27=0 8(x+5)^3=27 (x+5)^3=27/8 x+5=3/2 x=-7/2