Question

resolva as equaçoes do 1 grau com uma incognita A) -6x= -4 B)3n-17+7 C)4y+12=y-10 D)2,5y=10 E)5-7x=2x-5 F)5x-3+x=3x-2_1

Answer 1

a)

- 6x =  - 4  (-1)
6x = 4
x =   4  (:2)
      ------
        6   (:2)

x =   2
      -----
        3 

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
b) 

3n - 17 = 7
3n = 7 + 17
3n = 24
n = 24/3
n = 8

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c) 
4y + 12 = y - 10
4y - y = - 10 - 12
3y = - 22
y = - 22/3

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
d)

2,5y = 10
y = 10 / 2,5
y =  10     .  10   
      -------  
       2,5       10

y = 100
      -------
       25

y = 4

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
e)
5 - 7x = 2x - 5
5 + 5 = 2x + 7x
10 = 9x
9x = 10
x = 10/9

¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
f) 
5x - 3 + x = 3x - 2 - 1
5x + x - 3 = 3x - 3
6x - 3 = 3x - 3
 6x - 3x = - 3 + 3
3x = 0
x = 0/3
x = 0