Question

If $aϵ\{-1,2,3,4,5\}$ and $bϵ\{0,3,6\},$ write the set of all ordered pairs (a, b) such that a + b = 5.

Answer 1

We have,

a + b = 5

$\Rightarrow a=5-b$

$\therefore b=0\Rightarrow a=5-0=5,$

$b=3\Rightarrow a=5-3=2,$

$b=6\Rightarrow a=5-6=-1,$

Hence, the required set of ordered pairs