Odpowiedź :
a)
[tex]a = 5a + 3\\b = 3a-6\\\\Ob = 2(a+b)\\\\Ob = 2(5a+3+3a-6) \\\\Ob = 2(8a-3)\\\\\boxed{Ob = 16a - 6}[/tex]
b)
[tex]a = 4x+7\\r = 7x-4\\\\Ob = a+2r\\\\Ob = 4x+7 +2(7x-4)\\\\Ob = 4x+7 +14x-8\\\\\boxed{Ob = 18x-1}[/tex]
a)
[tex]a = 5a + 3\\b = 3a-6\\\\Ob = 2(a+b)\\\\Ob = 2(5a+3+3a-6) \\\\Ob = 2(8a-3)\\\\\boxed{Ob = 16a - 6}[/tex]
b)
[tex]a = 4x+7\\r = 7x-4\\\\Ob = a+2r\\\\Ob = 4x+7 +2(7x-4)\\\\Ob = 4x+7 +14x-8\\\\\boxed{Ob = 18x-1}[/tex]