Question

aflati nnumerele rationale a, b, c stiind ca sunt direct proporționale cu 3, 5 , 8 si ca verifica egalitatea 2a+3b-c =52

Answer 1

{a,b,c} d.p {3,5,8}

$\frac{a}{3}= \frac{b}{5}= \frac{c}{8}=k$ ⇒ a=3k; b=5k; c=8k

2a+3b-c=52
2*3k+3*5k-8k=52
6k+15k-8k=52
13k=52
k=4 ⇒ a=3*4=12
            b=5*4=20 
            c=8*4=32