Question

Determine o zero de cada função:
a) f(x) = x - 5
b) f(x) = - x + 4
c) f(x) = 1/2x - 1
d) f(x) = 1 - 4x
e) f(x) = - 2x -5
f) f(x) = 2 - 3x/5

Answer 1

a) f(x) = x - 5

0 = x - 5
5 = x
x = 5
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b)
f(x) = - x + 4
0 = - x + 4
x = 4

*************************
c)
f(x) = 1/2x - 1
0 =  1  x - 1
      ----
        2

1 =   1      x
       -----
         2

1.2 = x
2 = x
x = 2

***********************
d)
f(x) = 1 - 4x

0 = 1 - 4x
4x = 1
x = 1/4

*********************
e)
f(x) = - 2x -5

0 = - 2x - 5
2x = - 5
x = - 5/2

***************************
f) f(x) = 2 - 3x/5

0 = 2 - 3x
          ------
             5

3x      =   2
------
  5

3x = 5.2
3x = 10
x = 10/3

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