Four employees can wash 20 service vehicles in 5 hours. what is the unit rate

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

[15 points]find the quotient with the restrictions. (x^2 - 2x - 3) (x^2 + 4x + 3) ÷ (x^2 + 2x - 8) (x^2 + 6x + 8)

Use complete sentences to differentiate between a regular tessellation, and a pure tessellation. be sure to include specific types of polygons in your explanation.