Question

determinati elementele multimii A={x E N I11I(2x+45)si x mai mic sau egal cu 40}

Answer 1

A={x ∈N I11I(2x+45)si x ≤40}
observam ca x>4
2x+45=11*5=> x=5
2x+45=11*6=> x∉N
2x+45=11*7=> x=16
2x+45=11*8=> x∉N
2x+45=11*9=> x=27
2x+45=11*10=> x∉N
2x+45=11*11=> x=38
2x+45=11*12=> x∉N
2x+45=11*13=> x=49>40

=> A={5,16,27,38}