Which equation matches the table of values?

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

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?

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15