Solution - Simplification or other simple results

Step  1  :

Equation at the end of step  1  :

  ((3•7x2) +  x) -  2

Step  2  :

Trying to factor by splitting the middle term

 2.1     Factoring  21x²+x-2 

The first term is,  21x²  its coefficient is  21 .
The middle term is,  +x  its coefficient is  1 .
The last term, "the constant", is  -2 

Step-1 : Multiply the coefficient of the first term by the constant   21 • -2 = -42 

Step-2 : Find two factors of  -42  whose sum equals the coefficient of the middle term, which is   1 .

Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  -6  and  7 
                     21x² - 6x + 7x - 2

Step-4 : Add up the first 2 terms, pulling out like factors :
                    3x • (7x-2)
              Add up the last 2 terms, pulling out common factors :
                     1 • (7x-2)
Step-5 : Add up the four terms of step 4 :
                    (3x+1)  •  (7x-2)
             Which is the desired factorization

Final result :

  (7x - 2) • (3x + 1)