Ajutor va rog;Se considera ecuatia 5/2x-1=0 Cerinte:a) Are ecuatia data solutie in multimea M={0;-2;4}? si b) Ce concluzie trageti din faptul ca numarul 2/5∈Q are proprietatea 5/2·2/5-1=0? Nu inteleg deloc ce sa fac

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2014-10-20T21:54:00+03:00
2x-1∈D5
D5={1,5}
pt.2x-1=1⇒2x=1+1⇒x=2/2⇒x=1∉M
pt.2x-1=5⇒2x=5+1⇒x=6/2⇒x=3∉M
x∉M
b) 2/5∈Q 
dar 5/2·2/5-1=0⇒1-1=0⇒0=0∉Q
(5/2)orix-1=0
5x/2-1=0
5x/2=1
5x=1ori2
x=2/5=0,4 nu apartine multimii M