Odpowiedź
[tex]\displaystyle \left \{ {{x = -4~~~} \atop {f(x) = -5 + 2x}} \right\\\\\\\displaystyle \left \{ {{x = -4~~~~~~~~~~} \atop {f(x) = -5 + 2 \cdot (-4)}} \right\\\\\\\displaystyle \left \{ {{x = -4~} \atop {f(x) = -5 - 8}} \right\\\\\\\displaystyle \left \{ {{~~x = -4} \atop {f(x) = -13}} \right[/tex]
[tex]\displaystyle \left \{ {{x = 3~~~~~} \atop {f(x) = -5 + 2x}} \right\\\\\\\displaystyle \left \{ {{x = 3~~~~~~~} \atop {f(x) = -5 + 2 \cdot 3}} \right\\\\\\\displaystyle \left \{ {{x = 3~~~} \atop {f(x) = -5 + 6}} \right\\\\\\\displaystyle \left \{ {{~~~~x = 3} \atop {f(x) = 1}} \right[/tex]
[tex]\displaystyle \left \{ {{x = -1~~} \atop {f(x) = x^2 + 2x}} \right\\\\\\\displaystyle \left \{ {{x = -1~~~~~~~~~~~~~} \atop {f(x) = \left( -1 \right)^2 + 2 \cdot \left( -1 \right)}} \right\\\\\\\displaystyle \left \{ {{~x = -1} \atop {f(x) = 1 - 2}} \right\\\\\\\displaystyle \left \{ {{~~~~x = -1} \atop {f(x) = - 1}} \right[/tex]
[tex]\displaystyle \left \{ {{x = 2~~~~} \atop {f(x) = x^2 + 2x}} \right\\\\\\\displaystyle \left \{ {{x = 2~~~~~~~~~~~} \atop {f(x) = \left( 2 \right)^2 + 2 \cdot \left( 2 \right)}} \right\\\\\\\displaystyle \left \{ {{x = 2~} \atop {f(x) = 4 + 4}} \right\\\\\\\displaystyle \left \{ {{~~~~x = 2} \atop {f(x) = 8}} \right[/tex]
Szczegółowe wyjaśnienie