Which value for w make the equation true ?-4w=12

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?

State one method by which you can recognize a perfect square trinomial.

What is the value of the discrimination for the quadratic equation 0=×2+2+×2