Question 719446
You almost have it. We note that each part of the given expression has a 2 AND an a as a factor so first factor out the 2 to get
6*a+2*a^3-2-10*a^2 = 2*(3*a+a^3-1-5*a^2)
put the right side the reducing order to get
6*a+2*a^3-2-10*a^2=2*(a^3-5*a^2+3*a-1)
                  =2*(a^2-4*a+1)*(a-1)