1/13 with negative 1 exponent how does this equal 1?

How do i solve using pythagorean theorem?

Cherie measures and records the lengths and sizes of the same style of a sandal found at a shoe store. which equation can be used to determine the approximate shoe size, s, for a foot length of x inches? s = x – 2 s = 2x – 10 s = x + 6 s = 2x + 4

Atrucker had a load of grain containing 2 tons. she unloaded 1 ton and 1,200 pounds at the warehouse. how much grain does she still have left on the truck?