Răspuns :
[tex]a\;;\;b\;\;unde\;\;b=4a\;;\\
m_a=\frac{a+4a}{2}=70 \;\;\rightarrow\;\;5a=140\;\;\rightarrow\;\;a=28\;iar\;b=28*4=112\;;[/tex]
( a + b ) : 2 = 70
a + b = 70 x 2 = 140
b = 4a
a + 4a = 140
5a = 140
a = 28
b = 28 x 4 = 112
Proba: ( 28 + 112 ) : 2 = 140 : 2 = 70
a + b = 70 x 2 = 140
b = 4a
a + 4a = 140
5a = 140
a = 28
b = 28 x 4 = 112
Proba: ( 28 + 112 ) : 2 = 140 : 2 = 70
