Answer:
+7
Step-by-step explanation:
MnO41-
it is the same as Mn04 = -1
as generally known that the oxidation number of oxygen is -2, you'll insert -2 in the equation ie
Mn (-2 ×4) = -1
Mn (-8) =-1
add 8 to both sides
Mn -8+8 = -1+8
Mn = -1+8
Mn = +7