Find the value of n when

If (a-b)=-3 , (b-c)=5 and (c-a)=-2, then the value of .

If x = b+c -2a, y=c+a-2b, z=a+b-2c, then the value of x²+y²-z²+2xy is : 

If then the value of will be

If , then the value of

If x, y are two positive real number and  , then which of the following relations is true?

If 0.4 m + 0.8 n = 2.2 and 0.8 m + 0.4 n = 1.4, then the value of is equal to 

If a²+b²+c² = 2(a – b – c) – 3 then the value of 4a – 3b + 5c is