Answer:
For Answer 7 its the first one (x + 6) • (x - 7)
Explanation:
Step 1 :
Trying to factor by splitting the middle term
1.1 Factoring x2-x-42
The first term is, x2 its coefficient is 1 .
The middle term is, -x its coefficient is -1 .
The last term, "the constant", is -42
Step-1 : Multiply the coefficient of the first term by the constant 1 • -42 = -42
Step-2 : Find two factors of -42 whose sum equals the coefficient of the middle term, which is -1 .
-42 + 1 = -41
-21 + 2 = -19
-14 + 3 = -11
-7 + 6 = -1 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -7 and 6
x2 - 7x + 6x - 42
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (x-7)
Add up the last 2 terms, pulling out common factors :
6 • (x-7)
Step-5 : Add up the four terms of step 4 :
(x+6) • (x-7)
Which is the desired factorization
Final result :
(x + 6) • (x - 7)