Explicație pas cu pas:
x + y + z = 59
x = ⅓y
y = z - 20 => z = y + 20
[tex]\frac{y}{3} + y + y + 20 = 59 \\ \frac{y}{3} + 2y = 59 - 20 \\ \frac{7y}{3} = 39 \\ 7y = 3 \times 39 \\ = > y = \frac{117}{7} [/tex]
[tex]x = \frac{1}{3} \times \frac{117}{7} => x = \frac{39}{7} \\ [/tex]
[tex]z = \frac{117}{7} + 20 => y = \frac{257}{7} \\ [/tex]
