Question 1102873
Three years ago,
{{{R-3=3(D-3)}}}
{{{R-3=3D-9}}}
1.{{{R-3D=-6}}}
.
.
.
Three years from now,
{{{R+3=2(D+3)}}}
{{{R+3=2D+6}}}
2.{{{R-2D=3}}}
.
.

Subtract eq. 2 from eq. 1,
{{{R-3D-(R-2D)=-6-3}}}
{{{R-3D-R+2D=-9}}}
{{{-D=-9}}}
{{{D=9}}}
Now use either equation to solve for R.