Question

Dada as funções do primeiro grau, calcule:
A) f(x)=x+2
B) f(x)=1 x+1
2

C) f(x)=-x+2
D)f(x)=-1+3x
E) f(x)=1+2x
F) f(x)=-1-3x

Answer 1

A)
f(x) = x + 2
0 = x + 2
- 2 = x
x = - 2

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B)
f(x) =  x   + 1
         ----
          2

0 =  x   + 1
      ----
       2

- 1  =   x
          ------
           2

- 1.2 = x
- 2 = x
x = - 2

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C)
f(x) = - x + 2
0 = - x + 2
x = 2

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
D)
f(x) = - 1 + 3x
0 = - 1 + 3x
1 = 3x
3x = 1
x = 1/3
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨

E)
f(x) = 1 + 2x
0 = 1 + 2x
- 1 = 2x
2x = - 1
x = - 1/2

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
F)
f(x) = - 1 - 3x
0 = - 1 - 3x
3x = - 1 
x = - 1/3

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨