Respostas

2014-05-30T11:25:27-03:00
A.) 4x=4+16   4x=20   x=20÷4   x=5

B.) -2x= -1 - 3 .(-1)    2x=1+3  2x=4  x=4÷2    x=2

c.) 2x-8 = 4x+12   2x-4x=12+8   -2x=20 .(-1)    2x=20   x=20÷2   x=10

d.) -5x=20-15   -5x=5 .(-1)   5x= -5     x= -5÷ 5     x= -1
2014-05-30T11:44:24-03:00
a)4x-16=4 \\ 4x=4+16 \\ 4x=20 \\  \\  x = \frac{20}{4}  \\  \\ x = 5
S = {5}


b)-2x+3=-1 \\ -2x=-1-3 \\ -2x=-4 \\  \\ x= \frac{-4}{-2}  \\  \\ x=2
S = {2}


c)2.(x-4)=4.(x+3) \\ 2x-8=4x+12 \\ 2x-4x=12+8 \\ -2x=20 \\  \\ x= \frac{20}{-2}  \\  \\ x = -10
S = {- 10}


d)-5x+15=20 \\ -5x=20-15 \\ -5x=5 \\  \\ x= \frac{5}{-5}  \\  \\ x=-1
S = {- 1}