The error is that 9 shouldnt be written as nine it should be written as 3x3 or 3^2. So the answer should be 2^3 x 3^2 because 9 can be divided into even more prime factors of 72.
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