SOAL OLIMPIADE MATH Diketahui a + b = 3 dan a² + b² = 5, maka nilai a³ + b³ = .... #NoSpam

a + b = 3
a² + b² = (a + b)² - 2ab
2ab = (a + b)² - (a² + b²)
2ab = 3² - 5
2ab = 4
ab = 2

Maka
a³ + b³ = (a + b)(a² - ab + b²)
=>(3)(a² + b² - ab)
=>(3)(5 - 2)
=>(3)(3)
=> 9

semoga membantu, lumayan soalnya :v