a music teacher has 4 drum kits. Each kit has 2 drumsticks. Each drumstick cost $3. How many drumsticks does she have? What is the cost to replace them all?

Answer: The solutions are :

Our equation is

and we know that:

then we can write our equation as:

And using the identity:

where a = x and b = 2, then our equation is:

them, if x = 2 the first part is zero, so x = 2 is a solution, and now we need to see the second part in order to find the complex solutions.

Here we need to use Bhaskara:

if for a, b and c constants, then:

x =

in our problem we have:

So here we have two complex solutions: and .

Answer:

Solutions are 2,  -1 +  0.5 sqrt10 i  and -1 - 0.5 sqrt10 i

or 2,  -1 +  1.58 i  and -1 - 1.58i

(where the last 2 are equal to nearest hundredth).

Step-by-step explanation:

The real solution is x = 2:-

x^3 - 8 = 0

x^3 = 8

x = cube root of 8 = 2

Note that a cubic equation must have  a total of 3 roots ( real and complex in this case).  We can find the 2 complex roots by using the following identity:-

a^3 - b^3 = (a - b)(a^2 + ab + b^2).

Here  a = x and b = 2 so we have

(x - 2)(x^2 + 2x + 4) = 0

To find the complex roots we solve x^2 + 2x + 4 = 0:-

Using the quadratic formula x = [-2 +/- sqrt(2^2 - 4*1*4)] / 2

= -1 +/- (sqrt( -10)) / 2

= -1 +  0.5 sqrt10 i  and -1 - 0.5 sqrt10 i

The answer would be 20,000. Like rounding 21 to the nearest ten is 20 because it is lower than the middle number (25).