[tex]\it \mathbf{1}.\ a)\ \ f(x)=2x-1\\ \\ f(-1)=2\cdot(-1)-1=-2-1=-3\\ \\ f(0)=2\cdot0-1=-0-1=-1\\ \\ f(1)=2\cdot1-1=2-1=1\\ \\ f(2)=2\cdot2-1=4-1=3\\ \\ B=\{-3,\ -1,\ 1,\ 3\}\\ \\ \\ b)\ \ f(x)=x^2+1\\ \\ f(-\sqrt3)=(-\sqrt3)^2+1=3+1=4\\ \\ f(-\sqrt2)=(-\sqrt2)^2+1=2+1=3\\ \\ f(\sqrt2)=(\sqrt2)^2+1=2+1=3\\ \\ f(\sqrt3)=(\sqrt3)^2+1=3+1=4\\ \\ B=\{3,\ 4\}[/tex]
[tex]\it \mathbf{2}.\ f(x)=2x-3\\ \\ f(-1)=2\cdot(-1)-3=-2-3=-5\\ \\ f(0)=2\cdot0-3=0-3=-3\\ \\ f(1)=2\cdot1-3=2-3=-1\\ \\ f(2)=2\cdot2-3=4-3=1\\ \\ f(-1)+f(0)+f(1)+f(2)=-5-3-1+1=-8[/tex]
