Question 878454
<pre>
10k<sup>2</sup>+200k+937.5 = 0

a=10, b=200, c=937.5

{{{k}}}{{{""=""}}}{{{(-b +- sqrt( b^2-4ac ))/(2a) }}} 

{{{k}}}{{{""=""}}}{{{(-(200) +- sqrt( 200^2-4(10)(937.5) ))/(2(10)) }}}

{{{k}}}{{{""=""}}}{{{(-200 +- sqrt(40000-37500 ))/(20) }}} 

{{{k}}}{{{""=""}}}{{{(-200 +- sqrt(2500))/(20) }}}

{{{k}}}{{{""=""}}}{{{(-200 +- 50)/(20) }}}

Use the plus sign

{{{k}}}{{{""=""}}}{{{(-200 + 50)/(20) }}}

{{{k}}}{{{""=""}}}{{{(-150)/(20) }}}

{{{k}}}{{{""=""}}}{{{-15/2 }}} or -7.5, that's one solution.

Use the minus sign

{{{k}}}{{{""=""}}}{{{(-200 - 50)/(20) }}}

{{{k}}}{{{""=""}}}{{{(-250)/(20) }}}

{{{k}}}{{{""=""}}}{{{-25/2 }}}, or -12.5 that's the other solution.

Edwin</pre>