1) (2x+1)² + (-1)².(3x+1)²

=  4x² + 4x + 1 + 9x² + 6x + 1

= 13x² + 10x + 2

2) (2x+7)² + (-1)².(2x+3)²

= 4x² + 28x + 49 + 4x² + 12x + 9

= 8x² + 40x + 58

= 4x² + 20x + 29

3) -(x+5)² - (x-3)²

= -(x² +10x +25) - (x² -6x +9)

= -x² -10x -25 -x² +6x -9

= -2x² -4x -34

= -x² -2x -17

4) -(-2x+3)² - (5x-3)²

= -(-1)².(2x-3)² - (5x-3)²

= -(4x² -12x +9) - (25x² -30x +9)

= -4x² +12x -9 -25x² +30x -9

= -29x² +42x -18

5) -(2x-y)² - (x+3y)²

= -(4x² - 4xy +y²) - (x² +6xy +9y²)

= -4x² + 4xy -y² -x² -6xy -9y²

= -5x² -2xy -10y²

6) (3x-2)² - (3x-1)²

= 9x² -12x +4 - 9x² +6x -1

= -6x +3

7) -(2x+7y)² + (-1)².(2x+7y)²

= (2x+7y)².(-1+1)

= (2x+7y).0

=0

8) (x-2)² + (x-1)(x+5)

= x² -4x +4 + x² +5x -x -5

= 2x² -1

9) (x+2)² -(x+3)(x-3) +10

= x² +4x +4 -(x²-9) +10

= 4x +23

10) (x-1)² -(x-4)(x+4) +(x+3)²

= x² -2x +1 -x² +16 +x² +6x +9

= x² +4x +26