If `5b=6a+16 and 9b=7b-20`, then what is the value of `3a-2b`?

If a+2b=13 and 8a+b=20 , what is the value of 3a+b ?

If 5a=6b+7 and a -b =3, what is the value of b/2 ?

If A={1,2,3,4,5} and B={1,3,5,7,9} then find the value of (A-B)uu(B-A)

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) =______

If a = 2 and b = 5, the value of the expression 2a-[3a+{4b-(2a-b)+5a}-7b] is :