Question

Si ; a + b = 5 y ab = 7 hallar a3(al cubo) + b3(al cubo)

Answer 1

$(a+ b )^{3} =5^{3}$

$a^{3} + b^{3}+3ab(a+b)=125$

$a^{3} + b^{3}+3(7)(5)=125$

$a^{3} + b^{3}+105=125$

$a^{3} + b^{3}=20$