Simplify the following polynomial expression: \(3x^2 + 2x - 1 + 5x^2 - 3x + 4\)

Step 1 ：First, group like terms together: \( (3x^2 + 5x^2) + (2x - 3x) + (-1 + 4)\)

Step 2 ：Then, perform addition or subtraction within each group: \( 8x^2 - x + 3 \)