Question

Numerele x,y,z sunt direct proportionale cu 7,5 si 9 Daca 2x +3y -z = 100 atunci calculati x+y+z am nevoie va rog , dau funda

Answer 1

(x, y, z) dp.(7,5,9)

$\frac{x}{7} = \frac{y}{5} = \frac{z}{9} = k$

x=7k

y=5k

z=9k

2x+3y-z=100

2*7k+3*5k-9k=100

14k+15k-9k=100

20k=100

k=100:20

k=5

x=7k=7*5=35

y=5k=5*5=25

z=9k=9*5=45