Question

Даю 30баллов
Только ответ
Заранее спасибо

Answer 1

Ответ:

1.x=3

2.x1=-2,x2=3

3.15

4. B

Answer 2

Объяснение:

1.

$\frac{4x + 2}{7} + \frac{3x - 5}{4} = 3 \\ \\ 4(4x + 2) + 7(3x - 5) = 84 \\ 16x + 8 + 21x - 35 = 84 \\ 37x = 84 - 8 + 35 \\ 37x = 111 \\ x = \frac{111}{37} \\ x = 3$

ответ: 3

2.

$(x - 3)(6x + 5) = (x - 3)(2x - 3) \\ 6 {x}^{2} + 5x - 18x - 15 = 2 {x}^{2} - 3x - 6x + 9 \\ 6 {x}^{2} - 13x - 15 = 2 {x}^{2} - 9x + 9 \\ 6 {x}^{2} - 13x - 2 {x}^{2} + 9x = 9 + 15 \\ 4 {x}^{2} - 4x = 24 \\ 4 {x}^{2} - 4x - 24 = 0 \\ d = (4 {)}^{2} - 4 \times 4 \times ( - 24) = 16 + 384 = 400 \\ \\ x1 = \frac{4 + 20}{8} = \frac{24}{8} = 3 \\ \\ x2 = \frac{4 - 20}{8} = \frac{ - 16}{8} = - 2$

ответ: x1 = 3 , x2 = -2

3.

$\frac{( {5}^{3})^{5} \times 3^{16} }{9 \times {225}^{7} } = \frac{ {5}^{15} \times {3}^{16} }{ {3}^{ 2 } \times {45}^{7} \times {5}^{7} } = \frac{ {5}^{8} \times {3}^{14} }{ {45}^{7} } = \frac{ {5}^{8} \times {3}^{14} }{ {3}^{14} \times {5}^{7} } = \frac{ {5}^{8} }{ {5}^{7} } = {5}^{8 - 7} = 5$

ответ : 5

4.

$2(x - 3) - (x + 4) = x - 10 \\ 2x - 6 - x - 4 - x = - 10 \\ 2x - 2x = - 10 + 6 + 4 \\ 0 = 0$

ответ : x - любое число