Solve:- `(21-r)/(3)-(r)/(6)=(-(21-r))/(3)+(r)/(3)`.

In triangle ABC ,if (r_(1))/(6)=(r_(2))/(3)=(r_(3))/(2) ,where, r_(1),r_(2) and r_(3) are ex-radii, then find the value of (a)/(b)+(b)/(c)+(c)/(a) ?

r+r_(3)+r_(1)-r_(2)=

In an equilateral triangle the inradius and the circum-radius is connected by (1)r=4R(2)r=(R)/(2)(3)r=(R)/(3)(4)r=(r)/(sqrt(3))

If r_(1),r_(2),r_(3),r are in usual notation in Delta ABC then r_(1)r_(2)r_(3)-r(r_(1)r_(2)+r_(2)r_(3)+r_(3)r_(1))=

If r/(r_(1))=(r_(2))/(r_(3)) , then

If r_(1),r_(2),r_(3) are the radii of the escribed circlesof a Delta ABC and ifr is the radius of its incircle then r_(1)r_(2)r_(3)-r(r_(1)R_(2)+r_(2)r_(3)+r_(3)r_(1))=

If t_(r)=2^((r)/(3))+2^(-(r)/(3)), then sum_(r=1)^(100)(t_(r))^(3)-3sum_(r=1)^(100)(t_(r))+1=

((m-n)^(3)+(n-r)^(3)+(r-m)^(3))/(6(m-n)(n-r)(r-m))=?