Simplify the expression by adding the two polynomials: (2x2+3x−1)+(x2−5x+4)(2x^2 + 3x - 1) + (x^2 - 5x + 4)(2x2+3x−1)+(x2−5x+4).
3x2−2x+33x^2 - 2x + 33x2−2x+3
3x2+8x+33x^2 + 8x + 33x2+8x+3
2x2−2x+52x^2 - 2x + 52x2−2x+5
3x2−2x−53x^2 - 2x - 53x2−2x−5