Question

resolva as equaçoes
a) 5x-2-18+3x
b)2x-3+=12
c)3x+6=12
d)6x-10=2x+14
e)2x+5=x+9
f)12x-4=10x+3
g)10-3x=-2x
h)x.20=2x-4
i)4x-3x=2x+8
j)9-x+2=-5x+3+2x

Answer 1

a)
5x - 2 = 18 + 3x
5x - 3x = 18 + 2
2x = 20
x = 20/2
x = 10
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b)
2x - 3 = 12
2x = 12 + 3
2x = 15
x = 15/2
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c)
3x + 6 = 12
3x = 12 - 6
3x = 6
x = 6/3
x = 2
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d)
6x - 10 = 2x + 14
6x - 2x = 14 + 10
4x = 24
x = 24/4
x = 6
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e)
2x + 5 = x + 9
2x - x = 9 - 5
x = 4
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f)
12x - 4 = 10x + 3
12x - 10x = 3 + 4
2x = 7
x = 7/2
***********************************
g)
10 - 3x = - 2x
10 = - 2x + 3x
10 = x
x = 10
*************************************
h)
x.20 = 2x - 4
20x = 2x - 4
20x - 2x = - 4
18x = - 4
x = - 4   (:2)  =   - 2
       18   (:2)        9

****************************************
i)
4x - 3x = 2x + 8
x = 2x + 8
- 8 = 2x - x
- 8 = x
x = - 8
*****************************************
j)
9 - x + 2 = - 5x + 3 + 2x
9 + 2 - x = - 5x + 2x + 3
11 - x = - 3x + 3
11 - 3 = - 3x + x
8 = - 2x
- 2x = 8 ( - 1)
2x = - 8
x = - 8/2
x = - 4