Question

Resolva as seguintes equações :
a) 2x + 1 = 0
b) -x + 10 = 4
c) 2x/3 = 5
d) -1/5 = 2x - 3

Answer 1

2x + 1 = 0
2x = -1
x = -1/2

============

-x + 10 = 4
-x = 4 - 10
-x = -6
x = 6

============

2/3x = 5
2x = 15
x = 15/2
x = 7.5

============

-1/5 = 2x - 3
-1 = 10x - 15
-10x = -15 + 1
-10x = -14
x = 14/10
x = 7/5

Answer 2

a)

2x + 1 = 0
2x = - 1
x = - 1/2

b)

- x + 10 = 4
- x = 4 - 10
- x = - 6 ( - 1)
x = 6

c)

2x = 5
3
2x = 3.5
2x = 15
x = 15
      2

d)

- 1 = 2x - 3
5
- 1 = 5(2x - 3)
- 1 = 10x - 15
- 1 + 15 = 10x
14 = 10x
10x = 14 
x = 14 (:2) = 7
      10 (:2)   5

x = 7
     5