Question

Dada a lei de uma função f(x) = 5x -2, determine o valor de x de modo que : A) f(x) = 0 B) f(x) = 3 C) f(x) = -10 D) f(x) = 13

Answer 1

f(x) = 0
0 = 5x-2
x = 2:5 = 0,4

f(x) = 3
3 = 5x-2
3+2 = 5x
x = 5:5 = 1

f(x) = -10
-10 = 5x-2
-10+2 = 5x
-8 = 5x
x = -8:5 = -1,6

f(x) = 13
13= 5x-2
13+2 = 5x
x = 15:5 = 3

Answer 2

Resposta:

f(x) = 5x -2,

A)

f(x) = 0

0 = 5x - 2

-5x = -2

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

x = 2/5

B)

f(x) = 3

3 = 5x - 2

-5x = -2 - 3

-5x = -5

-x = -5/5

-x = -1 . (-1)

x = 1

C)

f(x) = -10

-10 = 5x - 2

-5x = -2 + 10

-5x = 8

-x = 8/5 . (-1)

x = -8/5

D)

f(x) = 13

13 = 5x - 2

-5x = -2 - 13

-5x = -15

-x = -15/5

-x = -3 . (-1)

x = 3