Question

Se considera functia f:R->R, f(x)=2x-3. Rezolvati ecuatia f(x+1)+f(x-1)=f(x)+f(3)

Answer 1

f(x+1)=2(x+1)-3=2x+2-3=2x-1 ; f(x-1)=2(x-1)-3=2x-5 si atunci rezulta => 2x-1+2x-5=2x-3+2*3-3 =>4x-6=2x => 2x=6 => x=3

Answer 2

Răspuns:

f(x)=2x-3

f(x+1)=2(x+1)-3=2x+2-3=2x-1

f(x-1)=2(x-1)-3=2x-2-3=2x-5

f(3)=2*3-3=6-3=3

Ecuatiadevine

2x-1+2x-5=2x-3+3

2x-6=0

2x=6║:2

x=3

Explicație pas cu pas: