Step-by-step explanation: for the case of (X) you only need to pass the 7i to the other side with the subtraction sign (-7i), then we get this equation:
x + 7i = y − yi
X = y - yi - 7i
in the case of the (Y), first we select the common multiple.
y - yi = y(1 - i)
if we replace it in the original expression, we get the following equation:
x + 7i = y(1 - i)
after that you can pass the value (1 - i) to the other side dividing,
