6 Kg = _Mg Please help me explain

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Which statements describe the solutions to the inequality x< -20 check all that apply. there are infinite solutions. each solution is negative. each solution is positive. the solutions are both positive and negative. the solutions contain only integer values. the solutions contain rational number values.

If f(x) = 3x2 - 2x+4 and g(x) = 5x + 6x - 8, find (f-g)(x).