Explicație pas cu pas:
x, y, z
y = 2x => x = y÷2 = 0,5y
z = y - 5
x + y + z = 0,5y + y + y - 5 = 2,5y - 5
[tex]m_{a} = \frac{x + y + z}{3} \\ = > \frac{2.5y - 5}{3} = 4.5 \\ [/tex]
[tex]2.5y - 5 = 4.5 \times 3 \\ 2.5y = 13.5 + 5 \\ 2.5y = 18.5 \\ y = 18.5 \div 2.5 = > y = 7.4[/tex]
[tex]x = 0.5y = 0.5 \times 7.4 = 3.7 \\ = > x = 3.7[/tex]
[tex]z = y - 5 = 7.4 - 5 = 2.4 \\ = > z = 2.4[/tex]
x = 3,7
y = 7,4
z = 2,4