Please answer it would rly help me out

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

Two lines parallel to the same plane are parallel to eachother

Me complete this proof! prove that a quadrilateral is a square. me with the steps for this proof.