Answer:
(a+2) (a-18)
Explanation:
Factoring a2-16a-36
The first term is, a2 its coefficient is 1 .
The middle term is, -16a its coefficient is -16 .
The last term, "the constant", is -36
Step-1 : Multiply the coefficient of the first term by the constant 1 • -36 = -36
Step-2 : Find two factors of -36 whose sum equals the coefficient of the middle term, which is -16 .
-36 + 1 = -35
-18 + 2 = -16 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -18 and 2
a2 - 18a + 2a - 36
Step-4 : Add up the first 2 terms, pulling out like factors :
a • (a-18)
Add up the last 2 terms, pulling out common factors :
2 • (a-18)
Step-5 : Add up the four terms of step 4 :
(a+2) • (a-18)
Which is the desired factorization