If `a=-8,b=-7,c=6`,verify that `(a+b)+c=a+(b+c)`

If a : b = c : d , prove that : (6a + 7b) (3c - 4d) = (6c + 7d) (3a - 4b) .

If a, b, c, d satisfy the equation a + 7b + 3c + 5d = 0 , 8a + 4b + 6c + 2d = - 16 , 2a + 6b + 4c + 8d =16 and 5a + 3b + 7c + d = -16 then the value of (a + d) (b + c) =______

Let A = (a,b,c),B= (b,d,e) and C = (e,f,g) , verify that : ( A nn B ) nn C = A nn (B nn C )

Let A = (a,b,c),B= (b,d,e) and C = (e,f,g) , verify that : (A uu B ) uu C = A uu ( Buu C )

Let A={1,2),B={1,2,3,4},C={5,6} and D={5,6,7,8} verify that AxxC is a subset of BxxD .

Let A = {1,2} ,B = {1,2 ,3 } ,c={5,6} and d={5,6,7 } verify that A xx C is a subset of B xx D

Let A = (a,b,c),B= (b,d,e) and C = (e,f,g) , verify that : A nn B = B nn A

Let A = (a,b,c),B= (b,d,e) and C = (e,f,g) , verify that : A uu B = B uu A

If A=|[3, 2], [7, 5]| and B=|[6 ,7], [8, 9]| , verify that (A B)^(-1)=B^(-1)A^(-1) .

If a=7,\ b=5,\ c=3, then the value of a^2+b^2+c^2-a b-b c-c a\ i s -12 (b) 0 (c) 8 (d) 12