Срочно!!! Решите пожалуйста

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28 просмотров

Срочно!!! Решите пожалуйста


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Алгебра (19 баллов) | 28 просмотров
Дан 1 ответ
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1.

{(x - 5)}^{2} = {x}^{2} - 10x + 25

{(6a + 7b)}^{2} = {36a}^{2} + 42ab + {49b}^{2}

(m + 3)(m - 3) = {m}^{2} - 9

(8m - 4n)(8m - 4n) = 64 {m}^{2} - 64mn + 16 {n}^{2}

2.

100 - {x}^{2} = (10 - x)(10 + x)

121 {a}^{2} - 25 {b}^{2} = (11a - 5b)(11a + 5b)

{(c - 8)}^{2} = {c}^{2} - 16c + 64

81 {a}^{2} - 72ab + 16 {b}^{2} = {(9 a- 4b)}^{2}

3.

{(2m + 6n)}^{2} - 5m(2m - n) = {4m}^{2} + 24mn + {36n}^{2} - {10m}^{2} + 5mn = - 6 {m}^{2} + 29mn \times + 36 {n}^{2}

4.

{x}^{2} - 49 = 0 \\ (x - 7)(x + 7) = 0 \\ x = + 7 \: \: \: x = - 7

{(x - 3)}^{2} - {(x + 1)}^{2} = 12 \\ {x}^{2} - 6x + 9 - {x}^{2} - 2x - 1 = 12 \\ - 8x + 8 = 12 \\ - 8x = 4 \\ x = - \frac{1}{2}

5.

{(m - 3)}^{2} - (m - 2)(m + 2) = {m}^{2} - 6m + 9 - {m}^{2} + 4 = - 6m + 13 \\ m = - 2.5 \\ - 6 \times ( - 2.5) + 13 = 15 + 13 = 28

6.

{(4x - 3)}^{2} - 25 = (4x - 3 - 5)(4x - 3 + 5) = (4x - 8)(4x + 2)

{(a - b - c)}^{2} - {(a + b - c)}^{2} = (a - b - c - a - b + c)(a - b - c + a + b - c) = ( - 2b)(2a - 2c)

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