Brain test, pick the biggest number

506+798
876-708
904x604

The length of a rectangle plus its width is 25 cm. the area is 156 square cm. what are the length and width of the rectangle? separate the answers with a comma.

What are the solutions of the system? solve by graphing. y = -x^2 - 3x + 2 y = -2x + 2

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?