(x²-4xy-221) factorise
Answers
Answer:
Factoring x2-4x-221
The first term is, x2 its coefficient is 1 .
The middle term is, -4x its coefficient is -4 .
The last term, "the constant", is -221
Step-1 : Multiply the coefficient of the first term by the constant 1 • -221 = -221
Step-2 : Find two factors of -221 whose sum equals the coefficient of the middle term, which is -4 .
-221 + 1 = -220
-17 + 13 = -4 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -17 and 13
x2 - 17x + 13x - 221
Step-4 : Add up the first 2 terms, pulling out like factors :
x • (x-17)
Add up the last 2 terms, pulling out common factors :
13 • (x-17)
Step-5 : Add up the four terms of step 4 :
(x+13) • (x-17)
Which is the desired factorization