Răspuns:
relatia de marimi direct proportionale
[tex]\frac{a}{b}[/tex]=[tex]\frac{c}{d}[/tex]= [tex]\frac{m}{n}[/tex] = k =12 [tex]\frac{a}{b}[/tex]=k a=k*b
[tex]\frac{a}{b}[/tex]= 12 => a= 12b c=12d m=12n
inlocuim in suma si obtinem
a+c+m= 12b+12d+12n= 12(b+d+m)
a)[tex]\frac{a+c+m}{b+d+n}[/tex]=12
b) a+c=12(b+d) [tex]\frac{a+c}{b+d}[/tex] =12
c) c+m=12(d+n) [tex]\frac{a+c}{b+d}[/tex] + [tex]\frac{c+m}{d+n}[/tex] = 12+12= 24
d) a+m=12(b+n) [tex]\frac{a+m}{b+n}[/tex] + [tex]\frac{a+c+m}{b+d+n}[/tex] =12+12=24
