Question

alguém me ajuda pfv ​

Answer 1

Resposta:

1. A) x = 2 ou x = 1

B) x = -2

2. A) f(x) = x - 4

B) f(x) = -4 - x / x - 1

3. A) D = R - {-3}

B) D = {x e R / x ≥ 8/7}

4. A) f(2) = 6

B) x = 3/2

C) f(3) + 2*f(4) - g(0) = 26

Explicação passo-a-passo:

1. A) x² - 3x + 2 = 0 (Bhaskara)

x = -(-3) + √(-3)² - 4*1*2 / 2*1

x = 3 + √9 - 8 / 2

x = 3 + √1 / 2

x = 3 + 1 / 2

x = 4 / 2

x = 2

ou

x = 3 - 1 / 2

x = 2 / 2

x = 1

B) 2x + 6 = 2

2x + 6 = 2

2x = 2 - 6

2x = -4

x = -4 / 2

x = -2

2. A) f(x) = x + 4

y = x + 4

x = y + 4

y = x - 4

B) f(x) = x - 4 / x + 1

y = x - 4 / x + 1

x = y - 4 / y + 1

x(y + 1) = y - 4

xy + x = y - 4

xy - y = -4 - x

y(x - 1) = -4 - x

y = -4 - x / x - 1

3. A) f(x) = 2x - 1 / 3 + x

3 + x ≠ 0

x ≠ -3

D = R - {-3}

B) f(x) = ³√7x - 8

7x - 8 ≥ 0

7x ≥ 8

x ≥ 8/7

D = {x e R / x ≥ 8/7}

4. A) f(2)

f(2) = 2 + 4

f(2) = 6

B) g(x) = 0

0 = -2x + 3

2x = 3

x = 3/2

C) f(3) + 2*f(4) - g(0)

3 + 4 + 2(4 + 4) - (-2)*0 + 3

7 + 8 + 8 - 0 + 3

15 + 8 + 3

23 + 3

26