Before you can work with an unknown number, you need to give it a name. 93 out of every 100 people will call it 'X'. It doesn't matter what you call it. You could call it "Ralph" if you wanted to. I'll call it 'Q'.
Now, take it one step at a time:
-- The mystery number: Q
-- Three times the number: 3Q
-- The sum of three times the number and four: 3Q + 4
-- Four times that sum: 4 (3Q + 4)
The question says that this is equal to 52, so the Big Equation is
First calculate the area of the floor, this would be 30*50 = 1500 square feet Now multiply the area by the cost for each square foot, so 1500*0.5 = $750
