Answer:
a² + b² = 5
Explanation:
given a + b = 3 and ab = 2
a + b = 3 ← square both sides
(a + b)² = 3² ← expand (a + b)² using FOIL
a² + 2ab + b² = 9, that is
a² + b² + 2ab = 9 ← substitute ab = 2
a² + b² + 2(2) = 9
a² + b² + 4 = 9 ( subtract 4 from both sides )
a² + b² + 4 - 4 = 9 - 4 , then
a² + b² = 5