Let's make c the subject of the formula first. From the eqn. 2c^2 = 2bc +ac/2. From the RHS of the eqn, we have 2c(b + a/4). We achieved this by seperating the variables interms of C. So 2c^2 = 2c(b +a/4). Then it follows that when we divide both sides by 2c; we have, (2c^2)/2c = b + a/4. Hence c = b +a/4. And b = c - a/4. 4b = 4(c -a/4) = 4c -4a/4. This means that 4b = 4c -a