What is 12.50 times 8 in long multiplication

Lilianna uses 3/4 calories per minute just by sitting. she uses 1 more calorie per minute by walking. lilianna uses a total of 12 1/4 calories walking to the park. lilianna uses the equation, d(.75+1)=12.25 to represent the situation. what does the variable d represent in the equation?

Ineed to know the answer to this algebra question.

The first floor of marcus’ house is 1,440 square feet. he will cover 1,033 square feet with wood and the rest with tile. a box of tiles will cover 11 square feet. how many boxes of tile does marcus need to buy to cover the floor?