Multiplying 2 equations together

Question

If $x+y=i$ and $a+b=i$ is the equation $(x+y)(a+b)=(i)(i)$ always valid/true?

Example. Let $x = 1, y=2, a=2, b=1, i=3$ \begin{equation} 1+2=3 \\2+1=3 \\(3)(3)=(3)(3) \end{equation}

Is there any edge cases where and equation = the same thing multiplied together be false?

Answer 1

The following always holds

$$(x+y)(a+b)=ii=i(x+y)=i(a+b)$$