Answer :
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.