If the maximum value of a function y = (M & # 178; - 1) x + M & # 178; - 5m-6 in the closed interval [- 1,2] is 1, find the value of M

If the maximum value of a function y = (M & # 178; - 1) x + M & # 178; - 5m-6 in the closed interval [- 1,2] is 1, find the value of M

Classification 1: m ^ - 1 > 0, M > 1 or m ^ - 1