Answer: M = [tex]\frac{x-2y}{x+y}[/tex]
Step-by-step explanation:
[tex]\frac{M(x+y)+4y}{x^{2}-xy-y^{2} } =\frac{(x+2y)}{x^{2} -xy-y^{2} }[/tex]
M (x + y) + 4y = x + 2y (Multiply [tex]x^{2} - xy-y^{2}[/tex] in both sides)
M (x + y) = x + 2y - 4y
M (x + y) = x - 2y (Divide (x+y) from both sides)
M = [tex]\frac{x-2y}{x+y}[/tex]