Question 1134044


{{{x^3 +3x^2-14x-20=0 }}}
{{{x^3 -2x^2+5x^2-4x-10x-20=0}}} 
{{{(x^3 +5x^2)-(2x^2+10x)-(4x+20)=0 }}}
{{{x^2(x +5)-2x(x+5)-4(x+5)=0 }}}
{{{(x + 5) (x^2 - 2 x - 4) = 0}}}

solutions:

if {{{(x + 5)= 0}}}=>{{{highlight(x=-5)}}}

{{{(x^2 - 2 x - 4) = 0}}}.....use quadratic formula

{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 

{{{x = (-(-2) +- sqrt( (-2)^2-4*1*(-4) ))/(2*1) }}}

 {{{x = (2 +- sqrt( 4+16 ))/2 }}} 

 {{{x = (2 +- sqrt( 20 ))/2 }}} 

{{{x = (2 +- sqrt( 4*5 ))/2 }}} 

{{{x = (cross(2)1 +- cross(2)sqrt( 5 ))/cross(2)1 }}} 


{{{x = (1 +- sqrt( 5 )) }}} 

solutions: {{{highlight(x = 1 + sqrt( 5 )) }}}  or {{{highlight(x = 1 - sqrt( 5 )) }}}