Question

Factor the polynomial: 54k^2-24

Answer 1

@jim_thompson5910 Help?

Answer 2

hint:

54k^2 - 24

6(9k^2 - 4)

Answer 3

Where did you get the 9k^2 in the second line?

Answer 4

I factored out 6 from the expression

Answer 5

54k^2 - 24

6*9k^2 - 6*4

6(9k^2 - 4) .. using the distributive property

Answer 6

@jim_thompson5910 oh okay I get it, but then there's no number that multipies to give -4 and adds to 9? thats where im stuck at

Answer 7

from here, you would use the difference of squares rule to factor

Answer 8

and 9k^2 - 4 is really 9k^2 + 0k - 4

so you need to find two numbers that multiply to 9*(-4) = -36 and add to 0, then you factor by grouping

or you can use the difference of squares rule to factor

Answer 9

the difference of squares rule?

Answer 10

difference of squares

a^2 - b^2 = (a - b)(a+b)

Answer 11

ex:

25x^2 - 49

(5x)^2 - (7)^2

(5x - 7)(5x + 7)


So 25x^2 - 49 factors to (5x - 7)(5x + 7)