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(3x - 9) (9x - 7)
= 27x² - 21x - 81x + 63
= 27x² - 102x + 63
(2x - 1) (8x + 5) + (7x + 1) (4x + 8)
= 16x² + 10x - 8x - 5 + 28x² + 56x + 4x + 8
= 16x² + 28x² + 10x + 56x + 4x - 8x - 5 + 8
= 44x² + 62x + 3
7x + 5 - 5 (3x - 9)
= 7x + 5 - 15x + 45
= 7x - 15x + 5 + 45
= - 8x + 50
4 - 4 (- 2x - 2) (3x - 2) - 2 (3x - 2) (2x - 2)
= 4 - 4 (- 6x² + 4x - 6x + 4) - 2 (6x² - 6x - 4x + 4)
= 4 + 24x² - 16x + 24x - 16 - 12x² + 12x + 8x - 8
= 24x² - 12x² - 16x + 24x + 12x + 8x + 4 - 16 - 8
= 12x² + 28x - 20
(4t - 5)² + (- 3t + 1) (5t + 2)
= 16t² - 40t + 25 - 15t² - 6t + 5t + 2
= 16t² - 15t² - 40t - 6t + 5t + 25 + 2
= t² - 41t + 27
(7x - 6)²
= 49x² - 84x + 36
(1 + 4z)² + (2 + 4z) (3 + 5z)
= 1 + 8z + 16z² + 6 + 10z + 12z + 20z²
= 16z² + 20z² + 8z + 10z + 12z + 1 + 6
= 36z² + 30z + 7
(5 + 5z)² + 4z (5 + z)
= 25 + 50z + 25z² + 20z + 4z²
= 25z² + 4z² + 50z + 20z + 25
= 29z² + 70z + 25
(1 + 5z)² + 4z (2 + z)
= 1 + 10z + 25z² + 8z + 4z²
= 25z² + 4z² + 10z + 8z + 1
= 29z² + 18z + 1
