Factor y^2-11y+28=0, then find the roots

Answer 1

Standard format:

ax2 + bx + c = 0 (replace x with whatever unknown you are using.

You have: y^2-11y+28=0

Factoring procedure:

1. First, recognize that the 2 constants (the factors of 28) will both be either + or -. This means that b will be a SUM of factors, rather than a difference.
2. List the factors of both a and c. Then look for a combination that give you b.

For your equation, the a factors are just 1 and 1, c (28) can be factored into (1, 28), (2, 14), and (4,7)----and the negative of all those.

4 and 7 give us 11 for the center term, so the factors are:

(y - 4)*(y - 7)

Setting each equal to 0, solve for the roots.