Question

trei coppi au impreuna 188 timbre copilul c are cu 7 timbre mai mult decat copilul a,iar copilul b are de 3 ori mai multe decat a si c la un loc
Cine pune calcul steluta maxima

Answer 1

a+b+c=188;
c=7+a;
b=3(a+c)

a+3(a+a+7)+7+a=188 ⇒ a+6a+21`+7+a=188⇒8a+28=188 ⇒
8a=188 -28⇒8a=160 ⇒a=160:8⇒a=20;
c=7+a ⇒c=7+20⇒c=27
b=3*(20+27)⇒b=3*47⇒b=141.

a   ←→
c   ←→$\frac{7}{}$                                                      $\left \{ {{} \atop {a+b+c=188}} \right.$
b   ←→←→←→←→←→←→$\frac{7}{} \frac{7}{} \frac{7}{}$

Answer 2

a+b+c=188
c=7+a
b=3(a+c)  dar c=7+a ⇒  b=3(a+7+a)=3(2a+7)
deci c=7+a  si  b=3(2a+7)
le inlocuim in prima
a+3(2a+7)+7+a=188
a+6a+21+7+a=188
8a=188-28
8a=160
a=20

dar c=7+a=7+20=27
c=27
b=3(2a+7)=3(40+7)=3×47=141
b=141
verificare
a+b+c=188
20+27+141=188
188=188
deci a=20, b=27 si c=141

a=/_________/
c=/________/+7
b=3(a+c)=/_________/+/_________/+/_________/+/_________/+/_________/+/_________/+7+7+7
a+b+c=188

/_________/+/________/+7+/_________/+/_________/+/_________/+/_________/+/_________/+/_________/+7+7+7=188

/_________/=(188-28):8

/_________/=20  deci
a=20
c=/________/+7=20+7=27
b=3(a+c)=3(20+27)=3(47)=141