Question

Calcule o valor da incógnita.
a) 9 ( x + 2 ) < 19

b) 5x + 10 > 15

c) 2x – 4 > 3 ( x – 8 ) d) x + 3 < 12 – 2x

Answer 1

Resposta:

Explicação passo a passo:

A

9 ( x + 2) < 19

9x + 18 < 19

9x < 19 - 18

9x < 1

x < 1/9

B

5x + 10 > 15

5x > 15 - 10

5x > 5

x > 1

C

2x – 4 > 3 ( x – 8 )

2x - 4 > 3x - 24

2x - 3x > - 24 + 4

- x > - 20 (-1)

x < 20

D

x + 3 < 12 – 2x

x + 2x < 12 - 3

3x < 9

x < 9/3

x < 3

Answer 2

Resposta:

$a)x<\frac{1}{9} \\\\b)x>1\\\\c)x<20\\\\d)x<3$

Explicação:

$a)9(x+2)<19\\\\\frac{9(x+2)}{9} <\frac{19}{9} \\\\x+2<\frac{19}{9} \\\\x+2-2<\frac{19}{9}-2\\\\x<\frac{1}{9} \\\\\\b)5x+10>15\\\\5x+10-10>0\\\\5x>15-10\\\\5x>5\\\\x>5:5\\\\x>1\\\\\\c)2x-4>3(x-8)\\\\2x-4>3x-24\\\\2x-4+4=0\\\\2x>3x-24+4\\\\2x>3x-20\\\\2x-3x>20-3x\\\\-x>-20\\\\(-x)(-1)<(-20)(-1)\\\\x<20$

$d)x+3<12-2x\\\\x+3-3=0\\\\x<12-2x-3\\\\x<-2x+9\\\\x+2x<9+2x\\\\x<9:3\\\\x<3$