1)a)2x-3=19;2x=19+3;2x=22;x=22:2;x=11.
b)5x-2=3x+12;il trecem pe -2,din relatia 5x-2,dupa egal ceea ce inseamna ca schimbam semnul din''-'' in '+‘‘→5x=3x+12+2;Acum il trecem pe 3x dupa egal→5x-3x=14;2x=24;x=12.
c)scuze nu inteleg T︵T
2)a)2x-1∈D12;D12=1,2,3,4,6,12;x={1,2}
b)x+3=2x-15;trecem +3 dupa egal→x=2x+15-3;acum trecem 2x dupa egal → 2x-x=12;x=12.
Gata:-)