How do you write w2+18w+77 in factored form?

2 Answers
Sep 17, 2015

(w+7)(w+11)is the factorised form of the expression.

Explanation:

w2+18w+77

We can Split the Middle Term of this expression to factorise it.

In this technique, if we have to factorise an expression like aw2+bw+c, we need to think of 2 numbers such that:

N1N2=ac=177=77
AND
N1+N2=b=18

After trying out a few numbers we get N1=7 and N2=11
117=77, and 11+7=18

w2+18w+77=w2+11w+7w+77

w2+11w+7w+77=w(w+11)+7(w+11)

=(w+7)(w+11)

Sep 17, 2015

Factor w2+18w+77

Ans: y = (w + 7)(w + 11)

Explanation:

I use the new AC Method (Socratic Search) that is simpler and that avoids the lengthy factoring by grouping.
y = w^2 + 18w + 77 = (w + p)(w + q).
The 2 numbers p and q have same sign. Compose factor pairs of 77.--> (1, 77)(7, 11). This sum is 18 = b. Then, p = 1 and q = 77.
Factored form y = (w + 7)(w + 11)