Question

1 resolva achando o valor de × : a) ×-3=2×+1 b) 5×+2=7×-8 c) 5×-2=-7×+8 d) 4×+2=5×-1 e) 4×+2=3×+1 f) 9×+1=10×-3 g) ×+2=5×-3 h) ×+3=2×-1.

Answer 1

a)

x - 3 = 2x + 1

x - 2x = 1 + 3

-x = 4 (-1)

x = -4

b)

5x + 2 = 7x - 8

5x - 7x = -8 - 2

-2x = -10 (-1)

2x = 10

x = 10/2

x = 5

c)

5x - 2 = -7x + 8

5x + 7x = 8 + 2

12x = 10

x = 10/12

x = 5/6

d)

4x + 2 = 5x - 1

4x - 5x = -1 - 2

-x = -3 (-1)

x = 3

e)

4x + 2 = 3x + 1

4x - 3x = 1 - 2

x = -1

f)

9x + 1 = 10x - 3

9x - 10x = -3 - 1

-x = -4 (-1)

x = 4

g)

x + 2 = 5x - 3

x - 5x = -3 - 2

-4x = -5 (-1)

4x = 5

x = 5/4

h)

x + 3 = 2x - 1

x - 2x = -1 - 3

-x = -4 (-1)

x = 4