How do you factor this?

0 ⤊

How do you factor this?

4x^2-21x-18

2007-08-16 12:35:17 · 4 answers · asked by NEpatriots12 2 in Science & Mathematics ➔ Mathematics

4 answers

(4x + 3) (x - 6) are the factors.
Check
4x(x - 6) + 3(x - 6)
4x² - 24x + 3x - 18
4x² - 21x - 18 as required.

2007-08-20 10:53:16 · answer #1 · answered by Como 7 · 0⤊ 0⤋

There are two possibilities.

Try (4x + something)(x - something)
Try (2x + something)(2x - something)

For the "somethings", try numbers that multiply together to make 18 (1 and 18, 2 and 9, or 3 and 6).

2007-08-16 19:44:20 · answer #2 · answered by Betsy D 3 · 0⤊ 0⤋

4x^2-21x-18
=4x^2+3x-24x-18
=x(4x+3)-6(4x+3)
=(4x+3)(x-6)

2007-08-16 19:44:46 · answer #3 · answered by Anonymous · 0⤊ 0⤋

(4x-3)(x+6)
x=3/4 or -6

2007-08-16 19:47:26 · answer #4 · answered by Dave aka Spider Monkey 7 · 0⤊ 0⤋