Math PicnicEvery sheet is a promise

Taking out a common factor

Practice Practice sheetNew questions
The question

24x² + 120x + 168

24x² + 120x + 168

24x² + 120x + 168
24120168
24:1234681224
120:12345681012152024304060120
168:12346781214212428425684168
GCF = 24
24(x² + 5x + 7)
24x² + 120x + 168=24(x² + 5x + 7)
  1. First look for a factor every term shares. The numbers here are 24, 120, 168 — find the biggest number that divides all of them.
  2. List what divides each one and look for the biggest they all share. 24: 1, 2, 3, 4, 6, 8, 12, 24 120: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120 168: 1, 2, 3, 4, 6, 7, 8, 12, 14, 21, 24, 28, 42, 56, 84, 168.
  3. The biggest number in all of those lists is 24. Take it out in front and divide every term by it: 24 ÷ 24 = 1, 120 ÷ 24 = 5, 168 ÷ 24 = 7.
  4. Check the bracket: x² + 5x + 7 — those numbers share nothing but 1, so nothing more comes out. 24x² + 120x + 168 = 24(x² + 5x + 7).

How it works.

  1. 01

    First look for a factor every term shares. The numbers here are 24, 120, 168 — find the biggest number that divides all of them.

  2. 02

    List what divides each one and look for the biggest they all share. 24: 1, 2, 3, 4, 6, 8, 12, 24 120: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120 168: 1, 2, 3, 4, 6, 7, 8, 12, 14, 21, 24, 28, 42, 56, 84, 168.

  3. 03

    The biggest number in all of those lists is 24. Take it out in front and divide every term by it: 24 ÷ 24 = 1, 120 ÷ 24 = 5, 168 ÷ 24 = 7.

  4. 04

    Check the bracket: x² + 5x + 7 — those numbers share nothing but 1, so nothing more comes out. 24x² + 120x + 168 = 24(x² + 5x + 7).

Pick another skill