Решите неравенство3x^2-15x= больше 0

3x^2 - 15x = 0 (factor out a 3x)  3x(x - 5) = 0 (separate parentheses and its coefficient into two equations)  3x = 0  x = 0  x - 5 = 0  x = 5  Check:  3x^2 - 15x = 0  3(0)^2 - 15(0) = 0  0 - 0 = 0  0 = 0 (this is true, so x = 0 is correct)  3x^2 - 15x = 0  3(5)^2 - 15(5) = 0  3(25) - 75 = 0  75 - 75 = 0  0 = 0 (this is true, so x = 5 is correct) 

3x^2-15x=>0 3x(x-5)=>0 по методу интервалов +++++++0-----5+++++++ (- бесконечности , 0] U [5, + бесконечность)