Original: (3x2 + 5x – 4) – (2x2 – 7x – 1)
3x^2 + 5x - 4 - 2x^2 - 7x - 1 < (Took parenthesis off)
First: Do 3x^2 - 2x^2 = x^2
x^2 + 5x - 4 - 7x - 1
Secondly: Do 5x - 7x = -2x
x^2 - 2x - 4 - 1
Third: Do -4 - - 1 = -4 +1 (Note: Subtracting 2 negatives will make it a positive)
Answer: x^2 - 2x -3
HOPE THIS HELPS! ^_^