We need to use distributive property to find the missing factors:

"The distributive property of multiplication says that a multiplication fact can be broken up into the sum of two other multiplication facts."

because 5+2 = 7.

So the correct answer are:
7 X 3 = ( 5 X 3 ) + ( 2 X 3 )
Then
7 X 3 = ( 2 X 3 ) + ( 5 X 3 )
because:
( 5 X 3 ) + ( 2 X 3 ) = ( 2 X 3 ) + ( 5 X 3 )
Also :
7 X 3 = ( 1 X 3) + ( 6 X 3 )
Because 7 x3 = (6+1) x 3 = 1 X 3) + ( 6 X 3 )