Solution - Simplification or other simple results

Step  1  :

Trying to factor by splitting the middle term

 1.1     Factoring  u²+6u-7 

The first term is,  u²  its coefficient is  1 .
The middle term is,  +6u  its coefficient is  6 .
The last term, "the constant", is  -7 

Step-1 : Multiply the coefficient of the first term by the constant   1 • -7 = -7 

Step-2 : Find two factors of  -7  whose sum equals the coefficient of the middle term, which is   6 .

Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  -1  and  7 
                     u² - 1u + 7u - 7

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

Final result :

  (u + 7) • (u - 1)