Question

If a+b = 5 and ab = 4, then the value of a³ - b³=​

Answer 1

$a + b = 5$

$ab = 4$

Therefore,

${a}^{3} + {b}^{3} = {(a + b)}^{3} - 3ab(a + b)$

$= {5}^{3} - 3 \times 4 \times 5$

$= 125 - 60$

$= 65$