What is 80% of 80? math class spring break packet

Which of the following represents a number squared is equal to twenty more than nine times that number ? a) x squared = 9x + 20 b) x squared = 20x + 9 c) x squared > 9 + 20x d) x squared = 9 + x + 20

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?

What are the solutions of the equation? 5z^2 + 9z - 2 = 0 a. 1, -2 b. 1, 2 c. 1/5, -2 d. 1/5, 2