This integral is solved by using the power rule. Move the the constant –3 to the outstide of the integral and convert the fraction 1/x3 to a negative exponent x–3. Then solve –3 ∫ x–3dx using the power rule with n = -3. Since n + 1 = –2, we get

∫ –  3
x3
 dx  
=  –3 ∫ x–3 dx
=  –3   1
–2
  x–2 + C
=   3
2x2
  + C