Question 549381
under what conditions it has been following matrix equality? 
( x y) * (1 1) = (1 1) * (x y)
( z w) * (0 1) = (0 1) * (z w) 
Answer: provided that z = 0 and x = w 
How?
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Equations:
x + 0*y = x + z
x +  y  = y + w
z + 0*w = z + w
z +  w = 0y + w
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From the 2nd row: x = w
From the 4th row: z = 0

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Cheers,
Stan H.