Example

Factoring y211y+28y^2 - 11y + 28

To factor the trinomial y211y+28y^2 - 11y + 28, apply the strategy for trinomials of the form x2+bx+cx^2 + bx + c.

Step 1 — Set up two binomials with first terms yy: (y)(y)(y\quad)(y\quad).

Step 2 — Find two numbers that multiply to 28 and add to -11. Because the constant term (28) is positive and the middle term's coefficient (-11) is negative, both numerical factors must be negative. List the negative factor pairs of 28 and check their sums:

  • -1 and -28: sum is -29
  • -2 and -14: sum is -16
  • -4 and -7: sum is -11

The pair -4 and -7 works because their product is 28 and their sum is -11.

Step 3 — Use -4 and -7 as the last terms of the binomials: (y4)(y7)(y - 4)(y - 7).

Step 4 — Check by multiplying: (y4)(y7)=y27y4y+28=y211y+28(y - 4)(y - 7) = y^2 - 7y - 4y + 28 = y^2 - 11y + 28.

The factored form is (y4)(y7)(y - 4)(y - 7).

0

1

Updated 2026-06-19

Tags

OpenStax

Intermediate Algebra @ OpenStax

Ch.6 Factoring - Intermediate Algebra @ OpenStax

Algebra

Related
Learn After