Question

3xsquare-x-10. factorise it please

Answer 1

Step by step solution :

Step  1  :

Equation at the end of step  1  :

(3x2 - x) - 10

Step  2  :

Trying to factor by splitting the middle term

 2.1     Factoring  3x2-x-10 

The first term is,  3x2  its coefficient is  3 .
The middle term is,  -x  its coefficient is  -1 .
The last term, "the constant", is  -10 

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

Step-2 : Find two factors of  -30  whose sum equals the coefficient of the middle term, which is   -1 .

     -30   +   1   =   -29     -15   +   2   =   -13     -10   +   3   =   -7     -6   +   5   =   -1   That's it


Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above,  -6  and  5 
                     3x2 - 6x + 5x - 10

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

Final result :

(x - 2) • (3x + 5)