28.3. a) (7 - a)²; б) (9 + b)²; в) (4 + n)²; г) (12 - р)2. 28.4. a) (-x + 1)²; б) (-2-3)2; в) (-п + 8)²; г) (-т – 10)². 28.5. a) (2a + 1)²; б) (3c - 2)²; в) (6x - 3)2; г) (7у + 6)². 28.6. a) (8x + 3y)²; в) (9р - 2q)²; б) (6m - 4n)²; г) (10z + 3t)². 28.7. a) (-3a + 5x)²; в) (-3m + 4n)²; б) (-6у - 2z)²; г) (-122 - 3t)². 28.8. a) (0,2x – 0,5a)²; 1 2 6) (m+3); 4 28.9. a) (x² + 1)²; 012 в) ба- 2 1 6 г) (10с + 0,1y)². в) (q² + 8)²;

28.3

1. a) \[(7 - a)^2 = 7^2 - 2 \cdot 7 \cdot a + a^2 = 49 - 14a + a^2\]

2. б) \[(9 + b)^2 = 9^2 + 2 \cdot 9 \cdot b + b^2 = 81 + 18b + b^2\]

3. в) \[(4 + n)^2 = 4^2 + 2 \cdot 4 \cdot n + n^2 = 16 + 8n + n^2\]

4. г) \[(12 - p)^2 = 12^2 - 2 \cdot 12 \cdot p + p^2 = 144 - 24p + p^2\]

28.4

1. a) \[(-x + 1)^2 = (-x)^2 + 2 \cdot (-x) \cdot 1 + 1^2 = x^2 - 2x + 1\]

2. б) \[(-z - 3)^2 = (-z)^2 + 2 \cdot (-z) \cdot (-3) + (-3)^2 = z^2 + 6z + 9\]

3. в) \[(-n + 8)^2 = (-n)^2 + 2 \cdot (-n) \cdot 8 + 8^2 = n^2 - 16n + 64\]

4. г) \[(-m - 10)^2 = (-m)^2 + 2 \cdot (-m) \cdot (-10) + (-10)^2 = m^2 + 20m + 100\]

28.5

1. a) \[(2a + 1)^2 = (2a)^2 + 2 \cdot 2a \cdot 1 + 1^2 = 4a^2 + 4a + 1\]

2. б) \[(3c - 2)^2 = (3c)^2 - 2 \cdot 3c \cdot 2 + 2^2 = 9c^2 - 12c + 4\]

3. в) \[(6x - 3)^2 = (6x)^2 - 2 \cdot 6x \cdot 3 + 3^2 = 36x^2 - 36x + 9\]

4. г) \[(7y + 6)^2 = (7y)^2 + 2 \cdot 7y \cdot 6 + 6^2 = 49y^2 + 84y + 36\]

28.6

1. a) \[(8x + 3y)^2 = (8x)^2 + 2 \cdot 8x \cdot 3y + (3y)^2 = 64x^2 + 48xy + 9y^2\]

2. б) \[(6m - 4n)^2 = (6m)^2 - 2 \cdot 6m \cdot 4n + (4n)^2 = 36m^2 - 48mn + 16n^2\]

3. в) \[(9p - 2q)^2 = (9p)^2 - 2 \cdot 9p \cdot 2q + (2q)^2 = 81p^2 - 36pq + 4q^2\]

4. г) \[(10z + 3t)^2 = (10z)^2 + 2 \cdot 10z \cdot 3t + (3t)^2 = 100z^2 + 60zt + 9t^2\]

28.7

1. a) \[(-3a + 5x)^2 = (-3a)^2 + 2 \cdot (-3a) \cdot 5x + (5x)^2 = 9a^2 - 30ax + 25x^2\]

2. б) \[(-6y - 2z)^2 = (-6y)^2 + 2 \cdot (-6y) \cdot (-2z) + (-2z)^2 = 36y^2 + 24yz + 4z^2\]

3. в) \[(-3m + 4n)^2 = (-3m)^2 + 2 \cdot (-3m) \cdot 4n + (4n)^2 = 9m^2 - 24mn + 16n^2\]

4. г) \[(-12z - 3t)^2 = (-12z)^2 + 2 \cdot (-12z) \cdot (-3t) + (-3t)^2 = 144z^2 + 72zt + 9t^2\]

28.8

1. a) \[(0.2x - 0.5a)^2 = (0.2x)^2 - 2 \cdot 0.2x \cdot 0.5a + (0.5a)^2 = 0.04x^2 - 0.2ax + 0.25a^2\]

2. б) \[\left(\frac{1}{4}m + 3n\right)^2 = \left(\frac{1}{4}m\right)^2 + 2 \cdot \frac{1}{4}m \cdot 3n + (3n)^2 = \frac{1}{16}m^2 + \frac{3}{2}mn + 9n^2\]

3. в) \[(6a - \frac{1}{6})^2 = (6a)^2 - 2 \cdot 6a \cdot \frac{1}{6} + \left(\frac{1}{6}\right)^2 = 36a^2 - 2a + \frac{1}{36}\]

4. г) \[(10c + 0.1y)^2 = (10c)^2 + 2 \cdot 10c \cdot 0.1y + (0.1y)^2 = 100c^2 + 2cy + 0.01y^2\]

28.9

1. a) \[(x^2 + 1)^2 = (x^2)^2 + 2 \cdot x^2 \cdot 1 + 1^2 = x^4 + 2x^2 + 1\]

2. б) \[(q^2 + 8)^2 = (q^2)^2 + 2 \cdot q^2 \cdot 8 + 8^2 = q^4 + 16q^2 + 64\]