given the ordered pairs (x, - 1) and (5, y) belong to the set {(a, b): b = 2a - 3}

To find: values of x and y

solving for first order pair

(x, - 1) = {(a, b): b = 2a - 3}

x = a and b = - 1

If b = - 1 then 2a = - 1 + 3 = 2

So, a = 1

x = 1

Similarly, solving for second order pair

(5, y) = {(a, b): b = 2a - 3}

a = 5 and y = b

If a = 5 then b = 2×5 - 3

So, b = 7

y = 7