Question 957430

if you need to solve {{{9n^2 + 4 +7n}}} first make it equal to zero

{{{9n^2 + 4 +7n=0}}}....rearrange terms

{{{9n^2+7n + 4 =0}}} ....compare to general form {{{ax^2+bx +c =0}}}, you see that {{{a=9}}}, {{{b=7}}}, and {{{c=4}}}

now plug it in quadratic formula 

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

{{{n = (-7 +- sqrt(7^2-4*9*4 ))/(2*9) }}} 

{{{n = (-7 +- sqrt(49-144 ))/18 }}} 

{{{n = (-7 +- sqrt(-95 ))/18 }}} 


{{{n = (-7 +- sqrt(95 )*i)/18 }}} 

exact solutions:


{{{n = (-7 + sqrt(95 )*i)/18 }}} 

{{{n = (-7 - sqrt(95 )*i)/18 }}}

approximate solutions:

{{{n = -7/18 + 9.75*i/18 }}} =>{{{n = -0.39 + 0.54*i }}} 

{{{n = -7/18 - sqrt(95 )*i/18 }}}=>{{{n = -0.39 - 0.54*i }}}