Odpowiedź:
a)
[tex]x = - 2 \: \: \: \: y = 3[/tex]
[tex]2 {x}^{2} y - 3xy + 1 = 2 \times ( - 2) ^{2} \times 3 - 3 \times ( - 2) \times 3 + 1 = 2 \times 4 \times 3 + 18 + 1 = 24 + 18 + 1 = 43[/tex]
b)
[tex]x = - 1 \: \: \: \: y = - 2[/tex]
[tex] - 4 {x}^{3} + 2 {y}^{2} - 4xy + x = - 4 \times {( - 1)}^{3} + 2 \times {( - 2)}^{2} - 4 \times ( - 1) \times ( - 2) + ( - 1) = 4 + 8 - 8 - 1 = 3[/tex]
c)
[tex]a = 4 \: \: \: \: b = - 2[/tex]
[tex]10 - ab + \frac{1}{2} {a}^{2} + \frac{3}{4} {b}^{2} = 10 - 4 \times ( - 2) + \frac{1}{2} \times {4}^{2} + \frac{3}{4} {( - 2)}^{2} = 10 + 8 + 8 + 3 = 29[/tex]
d)
[tex] x = 1 \: \: \: \: y = - 2 \: \: \: \: z = \sqrt{2} [/tex]
[tex]2xy {z}^{4} - 3 {z}^{2} + xy - 9 = 2 \times 1 \times ( - 2) \times { \sqrt{2} }^{4} - 3 \times { \sqrt{2} }^{2} + 1 \times ( - 2) - 9 = - 16 - 6 - 2 - 9 = - 33[/tex]
