Verified answer

Важная формула:

x² - y² = (x - y)(x + y)  ;   (x - y)(x + y) = x² + xy - xy - y² = x² - y².

Решение:

d² - 169c² = (d - 13c)(d + 13c).

169b² - 324c²d² = (13b - 18cd)(13b + 18cd).

81c² - 361x² = (9c - 19x)(9c + 19x).

16c⁴ - 4d⁴ = (4c² - 2d²)(4c² + 2d²) = 4(2c² - d²)(2c² + d²).

81a⁴ - 16 = (9a² - 4)(9a² + 4) = (3a + 2)(3a - 2)(9a² + 4).

324x²y² - 289 = (18xy - 17)(18xy + 17).

196c² - 225a²b² = (14c - 15ab)(14c + 15ab).

121c²b² - 400a² = (11cb  - 20a)(11cb + 20a).

9x⁴y² - 64 = (3x²y - 8)(3x²y + 8).