Решите пожалуста. Можно только ответы.24 бАлла.

$1)(c - 1)(c + 1) \\ 2) {(x - 2)}^{2} \\ 3)(5y - 2)(5y + 2) \\ 4) {(6a - 5b)}^{2}$

${x}^{2} - 9 - ( {x}^{2} - 8x + 16) = \\ {x}^{2} - 9 - {x}^{2} + 8x - 16 = \\ - 25 + 8x$

$(5x - 1)(x + 2) + 3(x - 4)(x + 4) \\ = 2 {(2x + 3)}^{2} - 8 \\ {5x}^{2} + 10x - x - 2 + 3 {x}^{2} - 48 = \\ 2( {4x}^{2} + 12x + 9) - 8$

${8x}^{2} + 9x - 50 = 8 {x}^{2} + 24x + 18 \\ - 8 \\ 8 {x}^{2} + 9x -50 - 8 {x}^{2} - 24x \\ - 10 = 0 \\$

$(3a - 1) {}^{2} - (a + 2) {}^{2} = \\ {9a}^{2} - 6a + 1 - {a}^{2} - 4a - 4 = \\ 8 {a}^{2} - 10a - 3$

$( {a}^{2} - 36)(36 + {a}^{2} ) - ( {a}^{4} + 4a \\ + 4) = {a}^{4} - 1296 - {a}^{4} - 4a - 4 = \\ - 1300 - 4a$

$( {a}^{2} - 36)(36 + {a}^{2} ) - ( {a}^{4} - {36a}^{2} \\ + 324) = {a}^{4} - 1296 - {a}^{4} + 36 {a}^{2} \\ - 324 = - 1620 + 36 {a}^{2}$

$- 1620 + 36 \times ( - \frac{1}{6} ) {}^{2} \\ = - 1620 + 36 \times \frac{1}{36} = - 1619$

7 не знаю