If `( a - 5 )^2 + ( b - 6 )^2 = 0 `, then find the value of ( a + b - 3 )

If a/b = ( 4/3 )^-2 ÷ ( 5/6 )^0 , find the value of ( a/b )^-2

If a/b = ( 4/5 )^-2 ÷ ( 4/5 )^0 , find the value of ( a/b )^-3

3.If a+b=6 then find the value of 1/2a+1/2b

If A : B = 1 : 2, B : C = 3 : 4 and C : D = 5 : 6, then find the value of D : C : B.

if U = {1, 2, 3, 4, 5, 6, 7, 8, 9}, B = { 2, 4, 6, 8} and C = {3, 4, 5, 6} then find the value of (B - C)'.

If [(a+b,2),( 5,a b)]=[(6, 2),( 5, 8)] , find the values of a and b .

If U = {1, 2, 3, 4, 5, 6, 7, 8, 9}, B = { 2, 4, 6, 8} and C = {3, 4, 5, 6} then find the value of (B -C)' .