Question

Factor the expression on the left side of the equation. Then solve the equation.

Answer 1

X³ - 2x² - 5x = 0

First, take common factor:

x(x^2 - 2x - 5 )= 0

Now use the quadratic formula to find the roots of the trinomial

x = [- b +/- √(b^2 - 4(a)(c)] / 2a

$x = \frac{2 +/- \sqrt{4 -4(1)(-5)} }{2}$

x = [2 +/-2√6 ]/2

x = 1 + √6 and x = 1 -√6

Then the solutions are:

x =0; x = 1 + √6; x = 1 - √6

That is the las option shown.