Question

atividade de Matemática:
a)9.(x-2)=9
b)-10+2.(x+1)=8
c)12-3.(x+2)=6
d)15-2.(x-1)=x
e)17-7.(x-1)=2×​

Answer 1

a)9.(x-2)=9

9x-18=9

9x=27

x=27/9

x=3

b)-10+2.(x+1)=8

-10+2x+2=8

-8+2x=8

2x=16

x=16/2

x=8

c)12-3.(x+2)=6

12-3x-6=6

12-3x=12

-3x=0

x=0

d)15-2.(x-1)=x

15-2x+2=x

15+2=2x+x

17=3x

x=17/3

x=5,666....

e)17-7.(x-1)=2x

17-7x+7=2x

24=9x

x=24/9

x=8/3

x=2,666...

Answer 2

Resposta:

a)

$9(x - 2) = 9 \\ \\ 9x - 18 = 9 \\ \\ 9x = 18 + 9 \\ \\ 9x = 27 \\ \\ x = \dfrac{27}{9} \\ \\ \green{ x = 3}$

b)

$- 10 + 2(x + 1) = 8 \\ \\ - 10 + 2x + 2 = 8 \\ \\ 2x = 8 + 10 - 2 \\ \\ 2x = 18 - 2 \\ \\ 2x = 16 \\ \\ x = \dfrac{16}{2} \\ \\ \green{ x = 8}$

c)

$12 - 3(x + 2) = 6 \\ \\ 12 - 3x - 6 = 6 \\ \\ 12 - 6 - 6 = 3x \\ \\ 12 - 12 = 3x \\ \\ 0 = 3x \\ \\ x = \dfrac{0}{3} \\ \\ \green{x = 0}$

d)

$15 - 2(x - 1) = x \\ \\ 15 - 2x + 2 = x \\ \\ 15 + 2 = x + 2x \\ \\ 17 = 3x \\ \\ \green{ x = \dfrac{17}{3} }$

e)

$17 - 7(x - 1) = 2x \\ \\ 17 - 7x + 7 = 2x \\ \\ 17 + 7 = 2x + 7x \\ \\ 24 = 9x \\ \\ x = \frac{24 \div 3}{9 \div 3} \\ \\ \green{ x = \dfrac{8}{3} }$

Bons Estudos!