a)2x+5=13
b))5x+10=3x+20
c)2•(x+5)=x+8
d)5x+8=3x+10
e)5•(x-3)=3•(x+5)
f)10•(x-5)=8•(x+4)
g)(x+4)/3=(x-4)/5
Soluções para a tarefa
a)2x+5=13 b) 5x+10=3x+20 c)2•(x+5)=x+8
2 x = 13 - 5 5x - 3x = 20 - 10 2x + 10 = x + 8
2x = 8 2x = 10 2x - x = 8 - 10
x = 8/2 x = 10/2 x = -2
x = 4 x = 5
d) 5x+8=3x+10 e)5•(x-3)=3•(x+5) f)10•(x-5)=8•(x+4)
5x - 3x = 10 - 8 5x - 15 = 3x + 15 10x - 50 = 8x + 32
2x = 2 5x - 3x = 15 + 15 10x - 8x = 32 + 50
x = 2/ 2 2x = 30 2x = 82
x = 1 x = 30/2 x = 82/2
x = 15 x = 41
g) ( x + 4 ) = ( x - 4 ) = tire o mmc
3 5
5 ( x + 4 ) = 3 ( x - 4 ) =
15
5 ( x -4 ) = 3 ( x - 4 )
5x + 20 = 3x - 12
5x - 3x = -12 -20
2x = -32
x = -32/ 2
x = -16