Question

un nr este de 2 ori mai mare decat altul , iar media aritmetica a nr este 15 . sa se determine cele 2 nr

Answer 1

a=2b<br />Ma=(2b+b):2=15<br />Ma=2b+b=15*2<br />Ma=3b=30<br />Ma=b=30:3<br />Ma=b=10<br />Ma(a+10):2=15<br />Ma=a+10=30<br />a=30-10<br />a=20

Answer 2

[tex]M_a_(_a,_b_)= \frac{a+b}{2} \\\ a=2b\\ ----------\\ 15= \frac{2b+b}{2} =\ \textgreater \ 2b+b=30=\ \textgreater \ 3b=30=\ \textgreater \ b=10\\\\ 15= \frac{a+10}{2} =\ \textgreater \ a+10=30=\ \textgreater \ a=30-10=\ \textgreater \ a=20[/tex]