Question

x^3 - 125. How do I factor it? @jim_thompson5910

Answer 1

have you learned the difference of cubes rule?

Answer 2

The difference is when you subtract a cube

Answer 3

have you learned this formula?
\[\Large a^3 - b^3 = (a-b)*(a^2+ab+b^2)\]

Answer 4

yes. I just learned it today.

Answer 5

ok you'll use this formula to factor

Answer 6

in this case, a = x and b = 5

since 5^3 = 125

Answer 7

ok. I got x(x^2-5)(x+25) as the answer.

Answer 8

\[\Large a^3 - b^3 = (a-b)*(a^2+ab+b^2)\]
\[\Large x^3 - 5^3 = (x-5)*(x^2+x*5+5^2)\]
\[\Large x^3 - 5^3 = (x-5)*(x^2+5x+25)\]
\[\Large x^3 - 125 = (x-5)*(x^2+5x+25)\]

Answer 9

I think you have to simplify after you fill in the pattern.

Answer 10

that's as simplified as it gets

Answer 11

we cannot factor `x^2 + 5x + 25`

Answer 12

Never mind, because in some problems you have to simplify.

Answer 13

if b was 10x we can factor.

Answer 14

I'm not sure what you mean

Answer 15

x^2 + 10x + 25 = (x+5)(x+5). it only works if there was a ten.

Answer 16

oh I see, well if b = 10, then b^2 would be 100

so that 25 would change to 100

Answer 17

The problem is not fair.