Question

sabendo que a³+b³=6 e ab x (a+b)=7 e que a,b ∈ R.
calcule a+b=

Answer 1

(a+b)³ = a³+b³ + 3a²b+ 3ab²

(a+b)³ = a³+b³ + 3• ab×(a+b)

(a+b)³ = 6 + 3• [7]

(a+b)³ = 27

a+b = ³√27

a+b = 3 <===©