f: R -> R , f(x)=ax+b
A(-1;2) ∈ Gf => f(-1)=2
f(-1)=a*(-1)+b=-a+b ==> -a+b=2
B(0;-3) ∈ Gf => f(0)=-3
f(0)=a*0+b=0+b=b ==> b=-3
-a+(-3)=2 <=> -a-3=2 <=> -a=2+3 <=> -a=5 |:(-1) <=> a=-5
Functia devine : f:R -> R , f(x)=-5x+(-3)=-5x-3
Sper ca te-am ajutat !