1)а) (2а - 1)^2 = 4a^2 - 4a + 1б) (x+3y)^2 = x^2 + 6xy + 9y^2в) (1/5x-y)(1/5x+y) = (1/25)x^2 - y^2
2)а) (c - 2)(c+3)-(c - 1)^2 = c^2 + 3c - 2c - 6 - (c^2 - 2c + 1) = c^2 + 3c - 2c - 6 - c^2 + 2c - 1 = 1б) 3(a+c)^2 - 6 ac = 3(a^2 + 2ac + c^2) - 6ac = 3a^2 + 6ac + 3c^2 - 6ac = 3a^2 + 3c^2в) (p-3)(p^2 +3p + 9) - p^3 = p^3 + 3p^2 + 9p - 3p^2 - 9p - 27 - p^3 = -27
1)
а) (2а - 1)^2 = 4a^2 - 4a + 1
б) (x+3y)^2 = x^2 + 6xy + 9y^2
в) (1/5x-y)(1/5x+y) = (1/25)x^2 - y^2
2)
а) (c - 2)(c+3)-(c - 1)^2 = c^2 + 3c - 2c - 6 - (c^2 - 2c + 1) = c^2 + 3c - 2c - 6 - c^2 + 2c - 1 = 1
б) 3(a+c)^2 - 6 ac = 3(a^2 + 2ac + c^2) - 6ac = 3a^2 + 6ac + 3c^2 - 6ac = 3a^2 + 3c^2
в) (p-3)(p^2 +3p + 9) - p^3 = p^3 + 3p^2 + 9p - 3p^2 - 9p - 27 - p^3 = -27