Răspuns: [tex]\color{red}\Large\boxed {\bf A+3C= 50}[/tex]
Explicație pas cu pas:
(*^▽^*) Salutare!
[tex]\large \bf A-B = 8[/tex]
[tex]\large \bf B+3C = 42[/tex]
[tex]\large\text{\bf Adunam cele doua relatii}[/tex]
[tex]\large \bf A-B +B+3C= 8+42[/tex]
[tex]\color{red}\Large\boxed {\bf A+3C= 50}[/tex]
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