Hello
x^3-5x+5=2x^2-5
x^3-2x^2-5x+10=0 rearranging like so:
x^3-5x-2x^2+10=0 and factoring 1st and 2nd pair...
x(x^2-5)-2(x^2-5)
(x-2)(x^2-5) now you can factor the term in the second parentheses...
(x-2)(x+)(x-)
So the roots are -2.24, 2, 2.2
Have a nice day