help me factor (5x^2+8x-4)?

2008-11-17 2:59 pm

回答 (9)

2008-11-17 3:06 pm
✔ 最佳答案
(5x-2)(x+2)

just get the factors of 4 and put them in the brackets and then figure our which signs go where
參考: catherine
2008-11-17 3:04 pm
5x^2+8x-4=
(x+2)(5x-2)
2008-11-17 3:49 pm
5x^2 + 8x - 4

Factor a trinomial.

(x + 2)(5x - 2)

Multiply using the FOIL Method to confirm (check or test) the answer.

x x 5x = 5x^2

x x -2 = -2x

2 x 5x = 10x

2 x -2 = -4

5x^2 - 2x + 10x - 4

5x^2 + 8x - 4

The answer:

(x + 2)(5x - 2)
2008-11-17 3:08 pm
5x² + 8x - 4 = 0
5x² + 10x - 2x -4 = 0
(5x-2) (x+2) = 0
x = 2/5 or -2
2008-11-17 4:13 pm
(5x - 2)(x + 2)
2008-11-17 3:11 pm
5x^2 + 8x - 4
= 5x^2 + 10x - 2x - 4
= (5x^2 + 10x) - (2x + 4)
= 5x(x + 2) - 2(x + 2)
= (x + 2)(5x - 2)
2008-11-17 3:11 pm
(5x-2)(x+2)

you can also use the quadratic equation. That way you do not need to guess the answers. You can work them out

i.e. (-b+-sqrt(-b^2-4ac))/2a

really famous formula
2008-11-17 3:10 pm
(5x-2)(x+2)
2008-11-17 3:09 pm
(5x^2+8x-4)

(x + 2)(5x - 2)

5x^2 - 2x + 10x - 4

5x^2 + 8x - 4

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