a) \[(x-3)(x+3) = x^2 - 3^2 = x^2 - 9\]
б) \[(-x-5)(x-5) = -(x+5)(x-5) = -(x^2 - 5^2) = -(x^2 - 25) = -x^2 + 25\]
в) \[(8-a)(a+8) = (8-a)(8+a) = 8^2 - a^2 = 64 - a^2\]
г) \[(1-4x)(1+4x) = 1^2 - (4x)^2 = 1 - 16x^2\]
д) \[(b-5)(b+5) = b^2 - 5^2 = b^2 - 25\]
e) \[(5b-7)(5b+7) = (5b)^2 - 7^2 = 25b^2 - 49\]
ж) \[(7+b)(7-b) = 7^2 - b^2 = 49 - b^2\]
a) \[x^2 - 36 = x^2 - 6^2 = (x-6)(x+6)\]
б) \[1 - a^2 = 1^2 - a^2 = (1-a)(1+a)\]
в) \[16 - x^2 = 4^2 - x^2 = (4-x)(4+x)\]
г) \[-y^2 + 81 = 81 - y^2 = 9^2 - y^2 = (9-y)(9+y)\]
д) \[\frac{1}{9} - b^2 = \left(\frac{1}{3}\right)^2 - b^2 = \left(\frac{1}{3} - b\right)\left(\frac{1}{3} + b\right)\]
e) \[ y^2 - \frac{25}{36} = y^2 - \left(\frac{5}{6}\right)^2 = \left(y - \frac{5}{6}\right)\left(y + \frac{5}{6}\right)\]
ж) \[0.81 - x^2 = (0.9)^2 - x^2 = (0.9 - x)(0.9 + x)\]
a) \[(m+5)^2 = m^2 + 2\cdot m \cdot 5 + 5^2 = m^2 + 10m + 25\]
б) \[(x-2)^2 = x^2 - 2 \cdot x \cdot 2 + 2^2 = x^2 - 4x + 4\]
в) \[(6-c)^2 = 6^2 - 2 \cdot 6 \cdot c + c^2 = 36 - 12c + c^2\]
г) \[(a+11)^2 = a^2 + 2 \cdot a \cdot 11 + 11^2 = a^2 + 22a + 121\]
д) \[ \left(\frac{1}{5} - m\right)^2 = \left(\frac{1}{5}\right)^2 - 2 \cdot \frac{1}{5} \cdot m + m^2 = \frac{1}{25} - \frac{2}{5}m + m^2\]
e) \[ \left(x+\frac{2}{3}\right)^2 = x^2 + 2 \cdot x \cdot \frac{2}{3} + \left(\frac{2}{3}\right)^2 = x^2 + \frac{4}{3}x + \frac{4}{9}\]
ж) \[(2x-3)^2 = (2x)^2 - 2 \cdot 2x \cdot 3 + 3^2 = 4x^2 - 12x + 9\]
a) \[x^2 + 2xy + y^2 = (x+y)^2\]
б) \[a^2 + 2a + 1 = (a+1)^2\]
в) \[n^2 + m^2 + 2mn = n^2 + 2mn + m^2 = (n+m)^2\]
г) \[-2xy + x^2 + y^2 = x^2 - 2xy + y^2 = (x-y)^2\]
д) \[81 - 18a + a^2 = a^2 - 18a + 81 = a^2 - 2 \cdot a \cdot 9 + 9^2 = (a-9)^2\]
e) \[a^2 - 12a + 36 = a^2 - 2 \cdot a \cdot 6 + 6^2 = (a-6)^2\]
ж) \[49 + 14x + x^2 = x^2 + 14x + 49 = x^2 + 2 \cdot x \cdot 7 + 7^2 = (x+7)^2\]
Ответ: Все задания выполнены!