The slope of a graph of photon energy versus photon frequency represents

The difference between two numbers is 15. when twice the smaller number is subtracted from three times the larger number, the difference is 58.what is the larger number?

Agas expands from an initial volume of 0.040 m^3 and an initial pressure of 210 kpa to a final volume of 0.065 m^3 while its temperature is kept constant. how much work is done by the system?

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?