Question

1. Numerele reale a,b,c verifica relatia $\frac{a}{5} - \frac{b}{7} + \frac{c}{11} =3,14$.
Calculati valoarea expresiei E= $3a- \frac{65}{91} ori b+( \frac{ \sqrt{5c} }{ \sqrt{11} } )^{2} -a: \frac{1}{2}$

Answer 1

a/5-b/7+c/11=3,14
E=3a-65b/91+(√5c/√11)²-a:1/2=
=3a-5b/7+5c/11-2a=
=a-5b/7+5c/11=
=5a/5-5b/7+5c/11=
=5(a/5-b/7+c/11)=
=5×3,14=15,7