Somebody link me a video on how to do proofs

Acircle has a circumference of 2 pi cm. which statement about the circumference and area is true? a comparison of the area and circumference is not possible since the area cannot be determined. the numerical values of the circumference and area of the circle are equal. the numerical value of the circumference is greater than the numerical value of the area. the numerical value of the circumference is less than the numerical value of the area.

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

Mr. t has been dating his girlfriend for one year nine months and six days how many hours has mr. t been in a relationship