zad. 1
a)
[tex](2x - \frac{1}{4} y) {}^{2} = 4x^{2} - xy + \frac{1}{16} y {}^{2} [/tex]
b) (4y - 3x)(3x + 4y) = 16y² - 9x²
c) (1 + 5y)² = 1 + 10y + 25y²
zad. 2
a) (2x - 3)² + (3x - 2)(3x + 2) = 4x² - 12x + 9 + 9x² - 4 = 13x² - 12x + 5
b) (1 + 6y)(1 - 6y) - (1 + 4y)² = 1 - 36y² - (1 + 8y + 16y²) = 1 - 36y² - 1 - 8y - 16y² = -52y² - 8y
