Explain why the greatest common factor of two numbers is sometimes one

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

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

The expression 1.01*1.005(^t) gives the amount of money, in thousands of dollars, in carter's savings account (t) years after he opens it. what does 1.01 represent in this expression?