Voltage sources in parallel Kirchhoff volage law
Is there a way to find an equivalent circuit for the sources V1,V2 and
  resistors R1 and R2??


If the outputs are connected and V1 = V2 then the sources can be connected. This means R1 and R2 are effectively in parallel.

This means it becomes a voltage source of V1 in series with R1 || R2 or, in the example given the series resistance is 135 ohms.