Question

If x + y = 6 and x3 + y3 = 72, find xy​

Answer 1

Answer:

=>(x+y) =6[Given]

Cubing both sides,

=>(x+y) ³=(6)³

=>(x)³+(y)³+3×x×y(x+y)=216

=>x³+y³+3xy×6=216[(x+y)=6]

=>72+18xy=216

=>18xy=216-72

=>18xy=144

=>xy=144/18

=>xy=8