a)
[tex]2x + 17 = 5 - 4x \\ 6x = - 12 | \div 6 \\ x = - 2 \\ \\ \\ 2 \times ( - 2) + 17 = - 4 + 17 = 13 \\ 5 - 4 \times ( - 2) = 5 + 8 = 13 \\ [/tex]
[tex]16 + 3 \times ( - 2) = 16 - 6 = 10[/tex]
Obwód
[tex]13 + 13 + 10 = 33[/tex]
Prawda
b)
[tex]2x + 17 = 16 + 3x \\ - x = - 1 | \times ( - 1) \\ x = 1[/tex]
[tex]2 \times 1 + 17 = 2 + 17 = 19 \\ 16 + 3 \times 1 = 16 + 3 = 19 \\ 5 - 4 \times 1 = 5 - 4 = 1[/tex]
Obwód
[tex]19 + 19 + 1 = 39[/tex]
Prawda