I need help with this question!?m

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?

Can someone me find the original price? the discount is 5% and the sale price is $68.40

The equations 2x-5y = -5 11x-5y = 15 9x+ 5y = 5 and 14x+ 5y = -5 are shown on the graph below. which system of equations has a solution of approximately (-0.6. 0.8)?