00:01
Here we are given the cubic equation x cubed minus 27.
00:03
We're asked for solutions for x.
00:06
So let's use this formula and how we break down a cube minus b cube to solve this equation.
00:15
So in this case, a is equals to x.
00:19
B is equals to 3.
00:21
So we have a minus b, a squared, plus ab, ab, plus a, b squared is equals to 0.
00:35
So our first solution, x is equals to 3.
00:41
Now for our second solution, we have x is equals to minus p plus minus square root of b squared minus 4a c over 2a.
01:00
So that's minus 3 over 2 plus minus square root of 9.
01:05
Minus 36 is minus 25 over 2...