Question

media aritmetica a trei numere este 13,4.unul din numere este 18.sa se afle media aritmetica a celorlalte doua numere

Answer 1

$ma_1=13,4 \\\\ ma_1=(a+b+c)/3 ; \ \ a\to 18 \\\\\\ \frac{18+b+c}{3}=13,4 \\\\ 18+b+c=3*13,4 \\\\ 18+b+c=40,2 \\\\ b+c=40,2-18 \\\\ b+c=22,2 \\\\ ma_2=\frac{b+c}{2} \longrightarrow \frac{\not 22,2}{\not 2} \\\\\\ \boxed{ma_2=11,1}$