Question 480038
2. {{{1/T =r/(R - r)}}} for R
{{{R-r=T*r}}}
{{{R=T*r+r}}}
{{{R=r(T+1)}}}
3.{{{7x^2 -2x +4 = 0}}}
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
{{{x = (-(-2) +- sqrt( (-2 )^2-4*7*4 ))/(2*7) }}} 
{{{x = (2 +- sqrt( -108 ))/14 }}}
{{{x[1] = (2 +i *sqrt( 108 ))/14%3 (2+6i*sqrt(3))/14=(1+3i*sqrt(3))/7 }}} 
{{{x[2] = (2 -i *sqrt( 108 ))/14=(2-6i*sqrt(3))/14=(1-3i*sqrt(3)) 2F7 }}} 
4. {{{F = KmM/r^2}}} for r
{{{F*r^2=KmM}}}
{{{r^2=KmM/F}}}
{{{r=sqrt(KmM/F)}}}
1.  {{{x^2 -8x^2 + 16 =0}}}
{{{-7x^2=-16}}}
{{{x^2=16/7}}}
{{{x[1]=sqrt(16/7)=4/sqrt(7)=4sqrt(7)/7}}%7 , {{{x[2]=-sqrt(16/7)=-4/sqrt(7)=-4sqrt(7)/7}}}