Odpowiedź:
a)
[tex]4( {x}^{2} - 3x + 4) - \frac{1}{2} (8 {x}^{2} - 4x + 6) = 4 {x}^{2} - 12x + 16 - 4 {x}^{2} + 2x - 3 = - 10x + 13 = - 10 \times 2 + 13 = - 20 + 13 = - 7[/tex]
b)
[tex]3( {x}^{2} + 2x - 2) + 2( {x}^{2} - 3x + 2) = 3 {x}^{2} + 6x - 6 + 2 {x}^{2} - 6x + 4 = 5 {x}^{2} - 2 = 5 \times {3}^{2} - 2 = 5 \times 9 - 2 = 45 - 2 = 43[/tex]
c)
[tex]x(3xy + x) - y(3 {x}^{2} + 2x - 2y) = 3 {x}^{2} y + {x}^{2} - 3 {x}^{2} y - 2xy + 2 {y}^{2} = {x}^{2} - 2xy + 2 {y}^{2} = ( \frac{1}{2} )^{2} - 2 \times \frac{1}{2} \times 2 + 2 \times {2}^{2} = \frac{1}{4} - 2 + 2 \times 4 = - 1 \frac{3}{4} + 8 = 6 \frac{1}{4} [/tex]
