Răspuns:
[tex](x + 4)(3x - 1) + {(x + 5)}^{2} - 4x(x - 3) = \\ = (x \times 3x + x \times ( - 1) + 4 \times 3x + 4 \times ( - 1)) + ( {x}^{2} + 2 \times x \times 5 + {5}^{2} ) - 4x \times x - 4x \times ( - 3) = \\ = 3 {x}^{2} - x + 12x - 4 + {x}^{2} + 10x + 25 - 4 {x}^{2} + 12x = \\ = - x + 12x + 10x + 12x - 4 + 25 = \\ = 33x + 21[/tex]
