<span>The order was just switched around, and it is multiplication, so we can conclude that it is the "Commutative Property of Multiplication"</span>
<span>Let x=one number and x+12= the other number. Together the numbers=54. Set up the equation: x+x+12=54; Combine the variables; 2x+12=54; Subtract 12 from both sides of the equation; 2x=42; Divide both sides of the equation by 2; x=21 is one number and 21+12=33 is the other number. Check: 2(21) +12=54; 42+12=54; 54=54.</span>
You can rule out A and C 6/6 makes 1 so that cancels so your answer is D