Question

Numerele pozitive a,b si c sunt direct proportionale cu numerele 5,6 si respectiv 4 a) scrieti crescator numerele a,b si c
b) Aratati ca 2b= 3c
c) daca 8a+ 3b - 2c= 500, aflati cele trei numere a,b si c.

Answer 1

a)a,b,c d.p. cu 5,6,4=> a/5=b/6=c/4=> b>a>c
b)b/6=c/4=>4b=6c=>2b=3c
c)a/5=b/6=>b=6a/5
a/5=c/4=>c=4a/5
8a+3b-2c=8a+3(6a/5)-2(4a/5)=8a+18a/5-8a/5=8a+10a/5=8a+2a=10a=500=> =>a=5
6a/5=b=>b=30/5=6
4a/5=c=>c=4