Find an explicit formula for the geometric sequence
1/2,-4, 32,-256, ..

a(n) =?

Some boys and girls were asked if they had a pet. one third of the group were boys. there were 20 boys. 20% of the girls had a pet. boys with a pet : girls with a pet = 1 : 5 i need to know how many girls there are.

What is the area of the shaded sector?

(c) a vine called the mile-a-minute weed is known for growing at a very fast rate. it can grow up to 0.5 ft per day. how fast in inches per hour can the mile-a-minute weed grow up to? show your work using the correct conversion factors.