Answer:x=6
Step-by-step explanation:Step-1 : Multiply the coefficient of the first term by the constant 1 • 18 = 18
Step-2 : Find two factors of 18 whose sum equals the coefficient of the middle term, which is -9 .
-18 + -1 = -19
-9 + -2 = -11
-6 + -3 = -9 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -6 and -3
x2 - 6x - 3x - 18
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (x-6)
Add up the last 2 terms, pulling out common factors :
3 • (x-6)
Step-5 : Add up the four terms of step 4 :
(x-3) • (x-6)
Which is the desired factorization