Question

1) Dada a função afim f(x)=2x +3, determine os valores de X para que:
a) f(x) = 1

b) f(x) = 0

c) f(x) = 1 sobre 3

Answer 1

a)
f(x) = 2x + 3
1 = 2x + 3
1 - 3 = 2x
- 2 = 2x
2x = - 2
x = -2/2
x = - 1

b)
f(x) = 0

0 = 2x + 3
- 3 = 2x
2x = - 3

x = - 3
       2

c)

f(x) = 1
         3

1 = 2x + 3
3

mmc: 3

1 = 3.2x + 3.3
3            3  

1 = 6x + 9
1 - 9 = 6x
- 8 = 6x
6x = - 8 (:2)
3x = - 4

x = - 4
        3

Answer 2

a) 2x + 3 = 1
2x = 1-3
2x = -2 --> x = -2/2 --> x = -1

b) 2x + 3 = 0
2x = -3
x = -3/2

c) 2x+3 = 1/3
6x + 9 = 1
6x = 1 - 9
6x = -8
x = -8/6
x = -4/3