Question

1.Resolva as inequacoes
A) 2 (x+10)>4x-30
B)5/2+3x <1/2+9x
C)7x+2x-5+20 <5x-(2x+4)

2.resolva as indicações e depois diga quais são as possíveis soluções:
A)18x-13>3x-50
B)3 (2x+10)-5-3x <5 (x-2)

Answer 1

1.
a) 2(x+10) > 4x - 30
2x + 20 > 4x - 30
2x - 4x > - 30 - 20
-2x > -50
$x > \dfrac{-50}{-2}$
x> 25


b) $\frac {5}{2}$+3x < $\frac{1}{2}+9x$
3x - 9x < $\dfrac {1}{2} - \dfrac{5}{2}$
6x < $\frac {-4}{2}$
6x < -2
x < $\dfrac{-2}{6}$
$x <-\dfrac {1}{3}$

c) 7x + 2x -5+20<5x-(2x+4)
9x-5x < -2x - 4 + 5 -20
4x + 2x < -19
6x < -19
$x < \dfrac{-19}{6}$

2.
a) 18x - 13 > 3x - 50
18x - 3x > -50 + 13
15x > -37
$x > \dfrac {-37}{15}$ 

b) 3(2x+10) - 5 -3x < 5 (x-2) 
6x + 30 - 5 - 3x < 5x - 10
3x - 5x < -10 - 25
-2x < -35
$x < \dfrac {-35}{-2}$
$x < \dfrac {35}{2}$

Espero ter ajudado, bons estudos !!

Answer 2

A) 2 (x+10)>4x-30 ==> 2x + 20 > 4x - 30 ==> 2x-4x > - 30 - 20

=> - 2x > - 50(-1) => 2x < 50 ==> x < 25
==================================================
B) 5 + 3x < 1 + 9x  ==> 5x + 6 < 1 + 18x ==> 5x - 18x < 1 - 6
     2            2

- 13x < - 5(-1) ==> 13x > 5 ==> x = 5/13
==================================================
C)7x+2x-5+20 <5x-(2x+4)  ==> 7x + 2x - 5+20 < 5x - 2x - 4

9x - 5x < - 4 + 15 ==> 4x < 11 ==> x > 11/4

2.resolva as indicações e depois diga quais são as possíveis soluções:

A)18x-13>3x-50  ==> 18x - 3x > - 50 + 13 ==> 15x > - 37 ==> x > - 37/15
======================================================
B) 3(2x+10)-5-3x <5 (x-2) ==> 6x + 30 - 5 - 3x < 5x - 2 

 3x - 5x < - 2 - 25 ==> - 2x < - 27(-1) ==> 2x > 27 ==> x > 27/2