a) f(x)=ax+b - functia de gradul I f(2x+3)=a(2x+3)+b f(x-2)=a(x-2)+b a(2x+3)+b - 2a(2x+3) - b = 26 2ax+3a+b-4ax-6a-b=26 // se reduce b. deci b=0; -2ax-3a=26 a(-2x-3)=26 ==> -2x-3=26 ==> -2x=29 ==> x=-29/2 a=26/(-2x-3) a=26/(29-3) a=26/26 a=1. Daca a=1 si b=0... f(x)=x