Question

СРОЧНО!!!!! 40 баллов!

Answer 1

Ответ:

1.

1)

$(a - 3)(b + 4) = a \times b + a \times 4 - 3 \times b - 3 \times 4 = ab + 4a - 3b - 12$

2)

$(x - 7)(x + 3) = x\times x + x \times 3 - 7 \times x - 7 \times 3 = {x}^{2} + 3x - 7x - 21 = {x}^{2} - 4x - 21$

3)

$(2y + 1)(5y - 6) = 2y \times 5y + 2y \times ( - 6) + 1 \times 5y + 1 \times ( - 6) = 10 {y}^{2} - 12y + 5y - 6 = 10 {y}^{2} - 7y - 6$

4)

$(4 {m}^{2} + 6)(4m - 6) = 4 {m}^{2} \times 4m + 4 {m}^{2} \times ( - 6) + 6 \times 4m + 6 \times ( - 6) = 16 {m}^{3} - 24 {m}^{2} + 24m - 36$

2.

1)

$(x - 2)(x - 11) - 2x(4 - 3x) = x \times x + x \times ( - 11) - 2 \times x - 2 \times ( - 11) - 2x \times 4 - 2x \times ( - 3x) = {x}^{2} - 11x - 2x + 22 - 8x + 6 {x}^{2} = 7 {x}^{2} - 21x + 22$

2)

$(a + 6)(a - 3) + (a - 4)(a + 5) = a \times a + a \times ( - 3) + 6 \times a + 6 \times ( - 3) + a \times a + a \times 5 - 4 \times a - 4 \times 5 = {a}^{2} - 3a + 6a - 18 + {a}^{2} + 5a - 4a - 20 = 2 {a}^{2} + 4a - 38$

3.

$(x + 6)(x - 1) - (x + 3)(x - 4) = 5x \\ x \times x + x \times ( - 1) + 6 \times x + 6 \times ( - 1) - \\ (x \times x + x \times ( - 4) + 3 \times x + 3 \times ( - 4)) = 5x \\ {x}^{2} - x + 6x - 6 - {x }^{2} + 4x - 3x + 12 = 5x \\ 6x + 6 = 5x \\ 6x - 5x = - 6 \\ x = - 6$

Answer 2

1) ответ: 7x² - 21+22

2) ответ: 2а² + 4а - 38

N3:

ответ: x= -6

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