a) \((5x - 2y^2)(5x + 2y^2)\) = \((5x)^2 - (2y^2)^2\) = \(25x^2 - 4y^4\)
б) \((2c - 3a^2)(3a^2 + 2c)\) = \((2c - 3a^2)(2c + 3a^2)\) = \((2c)^2 - (3a^2)^2\) = \(4c^2 - 9a^4\)
в) \((10p^3 - 7q)(10p^3 + 7q)\) = \((10p^3)^2 - (7q)^2\) = \(100p^6 - 49q^2\)
г) \((8d + 6c^3)(6c^3 - 8d)\) = \((6c^3 + 8d)(6c^3 - 8d)\) = \((6c^3)^2 - (8d)^2\) = \(36c^6 - 64d^2\)
a) \((4x^2 - 2y^2)(4x^2 + 2y^2)\) = \((4x^2)^2 - (2y^2)^2\) = \(16x^4 - 4y^4\)
б) \((10a^3 + 5b^2)(10a^3 - 5b^2)\) = \((10a^3)^2 - (5b^2)^2\) = \(100a^6 - 25b^4\)
в) \((3n^4 - m^4)(3n^4 + m^4)\) = \((3n^4)^2 - (m^4)^2\) = \(9n^8 - m^8\)
г) \((10m^8 + 8n^8)(10m^8 - 8n^8)\) = \((10m^8)^2 - (8n^8)^2\) = \(100m^{16} - 64n^{16}\)
a) \(69 \cdot 71\) = \((70 - 1)(70 + 1)\) = \(70^2 - 1^2\) = \(4900 - 1 = 4899\)
б) \(31 \cdot 29\) = \((30 + 1)(30 - 1)\) = \(30^2 - 1^2\) = \(900 - 1 = 899\)
в) \(89 \cdot 91\) = \((90 - 1)(90 + 1)\) = \(90^2 - 1^2\) = \(8100 - 1 = 8099\)
г) \(99 \cdot 101\) = \((100 - 1)(100 + 1)\) = \(100^2 - 1^2\) = \(10000 - 1 = 9999\)
a) \(58 \cdot 62\) = \((60 - 2)(60 + 2)\) = \(60^2 - 2^2\) = \(3600 - 4 = 3596\)
б) \(82 \cdot 78\) = \((80 + 2)(80 - 2)\) = \(80^2 - 2^2\) = \(6400 - 4 = 6396\)
в) \(42 \cdot 38\) = \((40 + 2)(40 - 2)\) = \(40^2 - 2^2\) = \(1600 - 4 = 1596\)
г) \(18 \cdot 22\) = \((20 - 2)(20 + 2)\) = \(20^2 - 2^2\) = \(400 - 4 = 396\)
Ответ: См. решения выше
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