What is half of 1 plus 500 dived by 2

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.

If angle b measures 25°, what is the approximate perimeter of the triangle below? 10.3 units 11.8 units 22.1 units 25.2 units

Factor the polynomial expression x6 – x3 – 20