What are the factors of x^2-81

A.) (x+9) (x-9)

B.) (x-9) (x-9)

C.) (x+3) (x-27)

D.) prime

Idont get this question can someone me solve it? ** the distance light travels in one second (1 light second) is about 1.86 ×10^5 mi. saturn is about 475 light-seconds from the sun. about how many miles from the sun is saturn..my guess is 8.83* 10^7 you so much

Under normal conditions, 1.5 feet of snow will melt into 2 inches of water. during a winter season high in the mountains, 301 feet of snow fell. how many inches of water will there be when the snow melts?

Acar travels at an average speed of 56 miles per hour. how long does it take to travel 196 miles