Odpowiedź:
[tex] - {x}^{2} - y + z - {x}^{2} = - 2 {x}^{2} - y + z[/tex]
[tex]3(5a + 4b) - 2(9a - 4b) = 15a + 12b - 18a + 8b = - 3a + 20b[/tex]
[tex]3 \sqrt{a} - 2 {a}^{2} + 2a(a - 3) = 3 \times \sqrt{4} - 2 \times {4}^{2} + 8(4 - 3) = 3 \times 2 - 2 \times 16 + 8 \times 1 = 6 - 32 + 8= -18[/tex]
