Question

if a+b=12 and ab=27 find the value of a^3+b^3​

Answer 1

a+b=12

b=12-a

ab=27

a(12-a) =27

12a-a2 =27

${a}^{2} -12a + 27 \\ {a}^{2} - 6a - 3a + 27 \\ a(a - 6) - 3(a - 6) = 0 \\( a - 3)(a - 6) = 0$

a=6/3

so a=6 b=3

${a}^{3} + {b}^{3 } = {3}^{3} + {6}^{3}$

=27+216

=243