If two sources do not have the same frequency, the current in the circuit can be obtained by  source transformation.

The statement you provided seems to be a mix of a statement and a question. However, I'll try to explain the concept of source transformation and how it might apply to a circuit with two sources of different frequencies.

Source transformation is a method used in circuit analysis where we transform a voltage source in series with a resistance into a current source in parallel with the same resistance, or vice versa. This is based on Ohm's law and the fact that the power delivered by the source remains constant.

Here are the steps:

1. Identify the part of the circuit you want to transform. This should be a voltage source in series with a resistor, or a current source in parallel with a resistor.

2. If you're transforming a voltage source to a current source, divide the voltage by the resistance to find the current. The resistance remains the same.

3. If you're transforming a current source to a voltage source, multiply the current by the resistance to find the voltage. Again, the resistance remains the same.

4. Replace the original part of the circuit with the transformed source.

However, when it comes to sources with different frequencies, things get a bit more complicated. The frequency of a source can affect the impedance of the circuit elements, which in turn affects the current in the circuit. If the frequencies are different, they can interfere with each other, causing a phenomenon known as beat frequency.

In such a case, source transformation can still be used, but the analysis might become more complex. You might need to analyze the circuit for each frequency separately, or use techniques from the field of signal processing to handle the mixed frequencies.

Please note that this is a simplified explanation and actual circuit analysis can become quite complex depending on the specifics of the circuit.