Compare: 8/12 to 6/9 which one is greater

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

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

Use circumcenter theorem to solve for the given values