a)
[tex]x=3\\\\x^2=3^2=3\cdot3=9\\\\-x^2+1=-1\cdot3^2+1=-1\cdot3\cdot3+1=-9+1=-8\\\\12-x=12-3=9[/tex]
b)
[tex]x=-4\\\\x^2=(-4)^2=(-4)\cdot(-4)=16\\\\-x^2+1=-1\cdot(-4)^2+1=-1\cdot(-4)\cdot(-4)+1=-16+1=-15\\\\12-x=12-(-4)=12+4=16[/tex]
c)
[tex]x=1\dfrac{1}{2}=\dfrac{3}{2}\\\\x^2=\Big(\dfrac{3}{2}\Big)^2=\dfrac{3}{2}\cdot\dfrac{3}{2}=\dfrac{9}{4}\\\\-x^2+1=-1\cdot\Big(\dfrac{3}{2}\Big)^2+1=-1\cdot\dfrac{3}{2}\cdot\dfrac{3}{2}+1=-\dfrac{9}{4}+1=-\dfrac{9}{4}+\dfrac{4}{4}=-\dfrac{5}{4}\\\\12-x=12-1\dfrac{1}{2}=10\dfrac{1}{2}[/tex]
Tabelka:
[tex]\begin{array}{|c|c|c|c|}x&x^2&-x^2+1&12-x\\3&9&-8&9\\-4&16&-15&16\\1\frac{1}{2}&2\frac{1}{4}&-1\frac{1}{4}&10\frac{1}{2}\end{array}[/tex]
