How many half inch tiles would you need to cover the top of a 7 1/2 by 5 1/2 box

Solve the equation 3x2 + 19x + 9 = 0 to the nearest tenth.

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.