Calculating the power supplied by the current and voltage sources
Generally the Power is nothing but the product of current and voltage


You are right !

You just have to calculate the voltage across the current source, and the current in the voltage source, multiply the related current and voltage, and you'll get the answers.


for the current source : the voltage is 12V (the same of the voltage source, because they are in parallel). The power is 6A * 12V = 72W
or the voltage source : you have first to calculate the current flowing in the source, which is the difference between the current in the resistor and the current of the current source. I = 4A - 6A = -2A. And the power is : -2A * 12V = -24W. The minus sign tells the voltage source will RECEIVE 24W


[ADDED]
Oh, and by the way : the power in the resistor is 12V * 4A = 48W. You can check that it is equal to the algebraic sum of the powers of the two sources:
48W = 72W + (-24W)