Question

6. Aflaţi numerele x, y, z dacă sunt direct proportionale cu: 2; 4 şi 8 iar z-x-y=30.​

Answer 1

Răspuns:

$\frac{x}{2} = \frac{y}{4} = \frac{z}{8} \\ x = 2k \\ y = 4k \\ z = 8k$

$z - x - y = 30 \\ 8k - 2k - 4k = 30 \\ 2k = 30 \\ k = 30 \div 2 \\ k = 15$

$x = 2k = 2 \times 15 = 30 \\ y = 4k = 4 \times 15 = 60 \\ z = 8k = 8 \times 15 = 120$

Answer 2

x,y,z d.p. 2;4;8
x/2=y/4=z/8=k
x=k*2=>x=2k
y=k*4=>y=4k
z=k*8=>z=8k
8k-4k-2k=30
2k=30
k=30/2
k=15
x=2k
x=30
y=4k
y=60
z=8k
z=120