Question

equações exponenciais​

Answer 1

a)

2ˣ = 128

2ˣ = 2⁷

x = 7

b)

3ˣ = 243

3ˣ = 3⁵

x = 5

c)

5ˣ = 1/625

5ˣ = 1/5⁴

5ˣ = 5⁻⁴

x = -4

d)

7ˣ = 1/343

7ˣ = 1/7³

7ˣ = 7⁻³

x = -3

e)

1/3²ˣ = 1/81

(1/3)²ˣ = 1/3⁴

(1/3)²ˣ = (1/3)⁴

2x = 4

x = 4/2

x = 2

f)

(1/2)³ˣ = 1/64

(1/2)³ˣ = 1/2⁵

(1/2)³ˣ = (1/2)⁵

3x = 5

x = 5/3

g)

7²ˣ = 7ˣ ⁻¹

2x = x - 1

x = -1

h)

5³ˣ = 5ˣ ⁺⁸

3x = x + 8

2x = 8

x = 8/2

x = 4

i)

3ˣ² ⁻⁵ = 81

3ˣ² ⁻⁵ = 3⁴

x² - 5 = 4

x² = 4 + 5

x = +-√9

x = +- 3

j)

5ˣ² ⁻¹ = 125

5ˣ² ⁻¹ = 5³

x² - 1 = 3

x² = 3 + 1

x = +-√4

x = +- 2