Solution - Simplification or other simple results

Step  1  :

Equation at the end of step  1  :

  ((2•5a2) -  13a) -  3

Step  2  :

Trying to factor by splitting the middle term

 2.1     Factoring  10a²-13a-3 

The first term is,  10a²  its coefficient is  10 .
The middle term is,  -13a  its coefficient is  -13 .
The last term, "the constant", is  -3 

Step-1 : Multiply the coefficient of the first term by the constant   10 • -3 = -30 

Step-2 : Find two factors of  -30  whose sum equals the coefficient of the middle term, which is   -13 .

Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  -15  and  2 
                     10a² - 15a + 2a - 3

Step-4 : Add up the first 2 terms, pulling out like factors :
                    5a • (2a-3)
              Add up the last 2 terms, pulling out common factors :
                     1 • (2a-3)
Step-5 : Add up the four terms of step 4 :
                    (5a+1)  •  (2a-3)
             Which is the desired factorization

Final result :

  (2a - 3) • (5a + 1)