Question

(x^2+2x)(x+3)+2x(x^2-x-1)-(3x-1)(x^2-x)

Answer 1

$(x {}^{2} + 2x)(x + 3) + 2x(x {}^{2} - x - 1) - (3x - 1)(x {}^{2} - x) \\ = x {}^{3} + 3x {}^{2} + 2x {}^{2} + 6x + 2x {}^{3} - 2x {}^{2} - 2x - (3x {}^{3} - 3x {}^{2} - 3x + x) \\ = x {}^{3} + 3x {}^{2} + 6x + 2x {}^{3} - 2x - (3x {}^{3} - 4x {}^{2} + x) \\ = x {}^{3} + 3x {}^{2} + 6x + 2x {}^{3} - 2x - 3x {}^{3} + 4x {}^{2} - x \\ = 0 \times x {}^{3} + 7x {}^{2} + 3x \\ = 7x {}^{2} + 3x$