Question

va rog ajutati ma cu ex 2*a+b=24;2*b+c=27;2*c+a=30 aflati A,B.C

Answer 1

daca aduni toate operatile rezulta 2*(a+b+c)+a+b+c=30+27+24
rezulta 3*(a+b+c)=81
a+b+c=27

ASTEPT CORONITA :)

Answer 2

$\displaystyle 2a+b=24 \\ b=24-2a \\ 2b+c=27 \\ c=27-2b \Rightarrow c=27-2(24-2a) \Rightarrow c=27-48+4a \Leftrightarrow \\ \Leftrightarrow c=4a-21 \\ 2c+a=30$
$a=30-2c \Rightarrow a=30-2(4a-21) \Rightarrow a=30-8a+42 \Leftrightarrow \\ \Leftrightarrow \displaystyle a+8a=30+42 \Rightarrow 9a=72 \Rightarrow a= \frac{72}{9} \Rightarrow a=8 \\ 2a+b=24 \Rightarrow 2 \cdot 8+b=24 \Rightarrow 16+b=24 \Rightarrow b=24-16 \Rightarrow b=8 \\ 2b+c=27 \Rightarrow 2 \cdot 8+c=27 \Rightarrow 16+c=27 \Rightarrow c=27-16 \Rightarrow c=11 \\ \boxed{a=8,b=8,c=11}$