Question

How do you solve 8x^3-27?

Answer 1

it needs to be equal to something for you to solve it

Answer 2

its equal to zero, sorry

Answer 3

convert it to the form (a^3 + b^3) = (a+b)(a^2-ab + b^2)

Answer 4

(2x + 3)(4x^2 - 6x + 9)...just distribute to get the final answer

Answer 5

so do i set the first equation to zero and solve then use the quadratic formula to solve the second equation to find the roots?

Answer 6

no! distribute....

Answer 7

i'm lost

Answer 8

oh wait...i was factoring :))) I should've been solving. Sorry for confusing you.

Transpose 27 to the other side.

8x^3 = 27
get the cube root

2x = 3
x = 3/2

Answer 9

there should be two more roots..

Answer 10

that's okay, thank-you

Answer 11

@cinar...i think this is a repetitive root

Answer 12

no, they are complex

Answer 13

\[\frac34(-1+i \sqrt{3})\quad and \quad \frac34(-1-i \sqrt{3})\quad are \,also\, roots\]