Sal bought a house for $78,524.60. twelve years later he sold the house for 2 3/4 times as much. what was the sale price of the house?

You have to divide your total by 4 to figure out what 1/4 of the price would be. That makes 1/4 of the price $19,631.15  So really you could just do $78,524.60 x2 to figure out the 2x  which is $157,049.20 and then do $19,631.15 x3 to figure out the 3/4 amount which is $58,893.45.  Then add the two numbers to get $215, 942.65