45 Cards 12 friends invited; 1/2 came 12 x 1/2=6 Let x stand for the number of cards each friend received Armando kept 3 6x = 45-3 6x = 42 __ __ 6 6 x = 7
The equation you can use is x + 3x = 428 with x as the number of cheeseburgers and 3x the number of hamburgers you solve for x and get 4x= 428 and x=107
F= 9t . This is because each square foot is 9 tiles so however many square feet would be t. For ex. If you wanted 3 square feet then it would be f= 9(3) f=27 so you would need 27 tiles