Question

If a ∈ [−1, 2, 3, 4, 5] and b ∈ [0, 3, 6], write the set of all ordered pairs (a, b) such that a + b = 5.

Answer 1

Given:
a ∈ [−1, 2, 3, 4, 5] and b ∈ [0, 3, 6]
We know:
−1 + 6 = 5, 2 + 3 = 5 and 5 + 0 = 5
Thus, possible ordered pairs (a, b) are {(−1, 6), (2, 3), (5, 0)} such that a + b = 5.