(x+6)(x-2)(x-1)=60 write a polynomial

For this case what you should do is:
 1) Multiplication of terms within parentheses correctly.
 2) Rewrite the expression respecting power properties.
 3) Add or subtract terms of equal power.
 Note: See attached image.
  
 x ^ 3 + 3x ^ 2 -16x - 48 = 0