No. This is not random sampling as the students chose are not chosen at random. Random sampling would be something done where each sample has equal probability of being chosen. Clearly this is not random sampling.
Adding the 2 equations will eliminate x because -4x + 4x = 0 so we get -14y = 28 y = -2 plug this into the second euqtion:- 4x + 14(-2) = -28 4x - 28 = -28 x = 0
