Question

Știind ca 2*(a+3b)+3c=131 iar c+2b=19,aflați a !

Answer 1

$2(a+3b)+3c=131 \\ 2a+6b+3b=131 \\ 2a+3(2b+c)=131 \\ 2a+3 \cdot 19=131 \\ 2a+57=131 \\ 2a=131-57 \\ 2a=74 \\ a=74:2 \\ \boxed{a=37}$