Question

Só a 3 plsssssssssssss

Answer 1

Resposta:

Explicação passo-a-passo:

a) Está apagada a parte de cima.

b) (5x - 15)/(x - 2) . 5/(x - 3) =

5(x - 3)/(x - 2) . 5/(x - 3) =   (x - 3) divide (x - 3) = 1

5/(x - 2) . 5 =

25/(x - 2).

c) (x² + 6x + 9)/2 . 7/(2x + 6) =

x² + 6x + 9 = 0 (achar as raízes)

Δ = b² - 4ac

Δ = 6² - 4.1.9

Δ = 36 - 36

Δ = 0.

x = (- b ± √Δ)/2a

x = (- 6 ± √0)/2.1

x = (- 6 ± 0)/2

x = - 6/2

x₁ = x₂ = - 3.

Fazendo o produto das raízes: x² + 6x + 9 = (x + 3).(x + 3).

(x² + 6x + 9)/2 . 7/(2x + 6) =

(x + 3).(x + 3)/2 . 7/2(x + 3) =  (x + 3) divide (x + 3)

(x + 3)/2 . 7/2 =

(7x + 21)/4.

d) (6a - 6b)/5 ÷ (a² - b²)/3 =

a² - b² = (a + b)(a - b)

6(a - b)/5 ÷ (a + b)(a - b)/3 =

6(a - b)/5 . 3/(a + b)(a - b) =

6 . 3/5(a + b) =

18/(5a + 5b).

e) (x² - 16)/3x . 7x²/(3x + 12) =

(x + 4)(x - 4)/3x . 7x²/3(x + 4) =

(x - 4)/9x . (7x²) =

(x - 4)/9 . (7x) =

(7x² - 28x)/9.

f) (12x - 3)/5y⁴ ÷ (4x² - x)/3y² =

3(4x - 1)/5y⁴ ÷ x(4x - 1)/3y² =

3(4x - 1)/5y⁴ . 3y²/x(4x - 1) =

3/5y⁴ . 3y²/x =

9/5xy².