Question

3- determine x:
a) 6x = 2x
b)2x - 5 = x + 1
c)2x + 3 = x + 4
d)5x + 7 = 4x + 10
e)4x - 10 = 2x + 2
f)4x - 7 = 8x - 2
g)2x +1 = 4x - 7
h)9x + 9 + 3x = 15
i)16x - 1 = 12x + 3
j)3x - 2 = 4

Answer 1

 
a) considerando x = 1
6 x 1 = 2 x 1
6 = 2
6/2 = 3 
x = 3

b) 2x - 5 = x + 1
2x - x = 5 + 1
x = 6

c) 2x + 3 = x + 4
2x - x = 4 - 3
x = 1

d) 5x + 7 = 4x + 10
5x - 4x = 10 - 7
x = 3

e) 4x - 10 = 2x + 2
4x - 2x = 10 + 2
2x = 12
x = 12 / 2 
x = 6

f) 4x - 7 = 8x - 2 
4x - 8x = -2 +7
-4x = 5
x = 5 / 4
x = 1,25

g) 2x +1 = 4x - 7 
2x -4x = - 7 - 1
-2x = - 8 (-1)
2x = 8
x = 8 / 2
x = 4

h) 9x + 9 + 3x = 15
9x + 3x = 15 - 9
12x = 6
x = 6 / 12
x = 0,5

i) 16x - 1 = 12x + 3
16x - 12x = 3 +1
4x = 4
x = 4 / 4
x = 1

j) 3x - 2 = 4
3x = 4 + 2
3x = 6
x = 6 / 3
x = 2