Answer:
STEP
1
:
Equation at the end of step 1
(5r2 - 14r) + 8
Step-2 : Find two factors of 40 whose sum equals the coefficient of the middle term, which is -14 .
-40 + -1 = -41
-20 + -2 = -22
-10 + -4 = -14 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -10 and -4
5r2 - 10r - 4r - 8
Step-4 : Add up the first 2 terms, pulling out like factors :
5r • (r-2)
Add up the last 2 terms, pulling out common factors :
4 • (r-2)
Step-5 : Add up the four terms of step 4 :
(5r-4) • (r-2)
Which is the desired factorization
Final result :
(r - 2) • (5r -4)
