The equation m^2x^2 - (m+n)x + n =0 has two equal real roots.show that n^2 + 2(m-2m^2)n + m^2 = 0. If n is real, find the range of values of m

Question

Please help me in this question 

Answer 1

Here is a hint:  if there are 2 equal roots, then the discriminant is zero.  the discriminant is B²-4AC, where A = m²,

B = -(m+n), and C = n.  Set the discriminant equal to zero and rearrange the terms to get the desired result.