Question

Determinati numerele naturale x,y,z stiind ca sunt direct proportionale cu 3, 4, 5, iar x+2y+3z=78.

va multumesc!

Answer 1

[tex]\{x,y,z\}dp\{3,4,5\}\Rightarrow\frac{x}{3}=\frac{y}{4}=\frac{z}{5}=k\Rightarrow x=3k,y=4k,z=5k\\ x+2y+3z=78\\ 3k+8k+15k=78\\ 26k=78\Rightarrow k=3\\ x=3k=9\\ y=4k=12\\ z=5k=15[/tex]

Answer 2

{x,y,z}d.p{3,4,5}=)x/3=y/4=z/5=K=)x=3k y=4k z=5k
x+2y+3z=78
3k+8k+15K=78
26k=78=)k=3
x=3k=)x=9
y=4k=)y=12
z=5k=)z=15