1) (b+6) (b-6) - 3 (b+2)

2) (3a-2) (3a+2) + (a-8) (a+8)

3) (5x-3y) (5x+3y) + (3x-5y) (3x+5y)

4) (c-2) (3-c) - (5-c) (5+c)

1) (b+6) (b-6) - 3 (b+2) = b²-36-3b-6=b²-3b-42

2) (3a-2) (3a+2) + (a-8) (a+8) = 9a²-4+a²-64=10a²-68

3) (5x-3y) (5x+3y) + (3x-5y) (3x+5y) = 25x²-9y²+9x²-25y²=34x²-34y²

4) (c-2) (3-c) - (5-c) (5+c) = 3c-c²-6+2c-25+c²=5c-31

(b + 6) (b - 6) - 3 (b + 2) = b ² - 36 - 3b - 6 = b² - 3b - 42

(3a - 2) (3a + 2) + (a - 8) (a + 8) = 9a ² - 4 + a² - 64 = 10a² - 68

(5x - 3y) (5x + 3y) + (3x - 5y) (3x + 5y) = 25x ² - 9y² + 9x² - 25y² = 34x² - 34y²

(c - 2) (3 - c) - (5 - c) (5 + c) = 3c - 6 - c ² + 2c - 25 + c² = 5c - 31