I'm having a lot of trouble with composite figures, and i have a whole worksheet to do. can anyone me with these? !

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?