Question

помогите пожалуйста аааааа​

Answer 1

Ответ:

1a) ... = 5

1b) ... = 7

2)... = 2a-16

3) ∠А = 24°, ∠В = 78°∠С = 78°

4) ... =3y(x - c)(x + c)

5) x = 2

Объяснение:

а)

$\frac{5^{3} {\cdot} {5}^{4} }{ {5}^{6} } = {5^{3 + 4 - 6} = 5^{7 - 6} = 5^{1} = 5 }$

б)

$\frac{7^{10} }{( {7}^{3})^3 } = \ \frac{7^{10} }{ {7}^{3 \cdot3}} = \frac{ {7}^{10} }{ {7}^{9} } = {7}^{10 - 9} = 7^{1} = 7$

2.

$a( a- 2) - ( a- 4)^{2} = \\ = {a}^{2} - 2a - ({a}^{2} - 8a + 16) = \\ = \cancel{{a}^{2}} {- }2a {- }\cancel{{a}^{2}} {+ }8a{ -} 16 = 2a - 16$

3.

Ответ: ∠А = 24°, ∠В = 78°∠С = 78°

4.

$\small3x^2y -3yc^2 = 3( {x}^{2} y - yc^2) = 3y( {x}^{2} - c^2) =\\ \small{=3y(x - c)(x + c) }$

5

$5(3+4x)=27+14x \\ 5 {\cdot}3 + 5 {\cdot}4x = 27+14x \\ 15 + 20x = 27 + 14x \\ 20x - 14x = 27 - 15 \\ 6x = 12 \\ x = \frac{12}{6} = 2$