Answer:
D = [tex]\frac{3R+T}{3}[/tex]
Step-by-step explanation:
given R = [tex]\frac{D-T}{3}[/tex]
multiply all terms on both sides to eliminate the fraction
3R = 3D - T ( add T to both sides )
3R + T = 3D ( divide both sides by 3 )
D = [tex]\frac{3R+T}{3}[/tex]