Originally Posted by
weasley74 I need help solving these equations;
6x^3+17x^2-3x-20=0
And
X^4-4x^3-7x^2+22x+24=0
Thank you
Hello,
as yannick has suggested try to find a rational solution for the first equation.
By trial and error you'll see that x = 1 is a solution. Thus (x -1) can be factored out of the LHS term of the equation. Use long division: Code:
(6x^3 + 17x^2 - 3x - 20) ÷ (x - 1) = 6x^2 + 23x + 20
-(6x^3- 6x^2)
---------------
23x^2 - 3x
-(23x^2 - 23x)
---------------
20x - 20
-(20x - 20)
------------
0
Now the remaining solutions must be in
$\displaystyle 6x^2 + 23x + 20 = 0$
With the 2nd equation start with x = -1. Use long division. Try to get another rational solution, use long division again until you have a quadratic equation which can be solved algebraically.