First, we need to get all of the r's on the same side. To do this, we need to subtract "r" from both sides.
0.25r - 0.125 + 0.5r - r = 0.5 + r - r
0.25r - 0.125 +0.5r - r = 0.5
Now, we need to add like terms.
0.25r + 0.5r - r - 0.125 = 0.5
-0.25r - 0.125 = 0.5
Now, we need to get the "r" variable by itself.
-0.25r - 0.125 + 0.125 = 0.5 + 0.125
-0.25r = 0.625
Now, we divide both sides by -0.25
(-0.25r) / (-0.25) = 0.625 / (-0.25)
r = -2.5