text: Q:
  
  Are there better alternatives for these buffers?
  
  I'm building a circuit that extract the DC component of an input signal, ,divide the DC component by 5, and finally add 2.5V it. 
  Here is the schematic of the circuit (the last op-amp is to invert the inverted signal):
  
  As you can see, I've added a voltage-follower buffer between the low-pass filter and the voltage-divider sub-circuit, and another similar buffer between the voltage-divider sub-circuit and the rest of the circuit. Without those buffers, the result would be wrong. 
  I want to build the circuit on a breadboard using LM741 chip as op-amp. So, I was wondering if there another way to implement those buffers that uses less physical space on the breadboard?
  
  A:
  
  An LM324 would be a better option. This has 4 op-amps in a single 14-pin package. This quad op-amp, and its sibling the dual LM358, are very popular general purpose op-amps. In large volume you can buy them for a few cents each. They do have their limitations, and will not do everything, but they are a good replacement for the 741.
  
  A:
  
  With a 1000 kohm resistor at the front end and with potentially 500 nA bias current required by the dinosauresque and crappy 741 you will immediately get an offset error of 0.5V. That kills it for me. Throw the 741 in the trash can and find something better.
  Given also that the 741 has an input resistance of typically 2 Mohms you have now another substantial error. I'm basically just running down the numbers in the data sheet to see how the 741 stacks up in your application.
  Supply current ~2mA is very wasteful these days - a lot of modern op-amps have massive DC accuracy and consumes virtually nothing in comparison to the 741 and, in all my very long years of using op-amps I can't remember one occasion on which I caused one to fail by either bad handling, soldering or the occasional misuse in ESD handling (not that I would encourage folk to mishandle any chip).
  Input offset voltage could give you a further 5 mV error (piddling against the bias current issue of course).
  Also you can combine stage 1, 2 and 3 and use only one op-amp but please don't use the 741 if you want any measure of accuracy.
  
  