What is the difference between a linear model and a linear equation?

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

Tan198=asin164=? how to solve this? ?

If np3 /nc2 = 6, find the value of n