Răspuns:
a) (3/4x + 2/9)² = (3/4x)² + 2 × 3/4x × 2/9 + (2/9)² = 9/16x² + 1/3x + 4/81
formula folosita : (a + b)² = a² + 2ab + b²
b) (-2/5x - 5/2)² = (-2/5x)² - 2 × (-2/5)x × 5/2 + (5/2)² = 4/25x² + 2x + 25/4
formula folosita : (a - b)² = a² - 2ab + b²
Explicatie pas cu pas:
