Question

Fie multimea A={ x ∈ IR I -10 < -3x + 5 < 14 } Multimea A ∩ N* are cardinalul egal cu...

Answer 1

-10< -3x+5< 14 /-5

-10-5< -3x+5-5< 14-5

-15< -3x < 9 /:(3)

-5< -x< 3 *(-1)

5>x> -3

x€(-3,5)

AΠ N*={1,2,3,4}

cardinalul este egal cu 4

Answer 2

A={ x ∈ IR I -10 < -3x + 5 < 14 }

-10< - 3x+5 <14 /-5

-15<-3x<9 / :(-3)

-3<x<5

=> x∈{-2,-1,0,1,2,3,4}

A={-2,-1,0,1,2,3,4}

A∩ℕ*={1,2,3,4}

CARDINALUL ESTE 4