Question

Determinați a,b,c știind 5a+3b=57;
axc=72;
bxc=108

Answer 1

a xc=72 =>a=72/c
b xc=108 =>b=108/c
Acum inlocuim in prima relatie : 5*72/c+3*108/c= 57
=>360+324 supra c= 57 =>684/c=57=>c=684/57=12
c=12
a x 12=72 |:12 =>a=6
b x 12=108 |:12 =>b=9 
Verificare :5a+3b=57 =>5*6+3*9 =30+27 =57(Adevarat ca in ipoteza)

axc= 6*12=72 (Adevarat)
b xc=9 x12=108(Adevarat)