Question

1-Corrija as questões (achar o erro e corrigir)
a)3x+2=x+12
3x+x= 12-2
2x=10
x=5



B)4.(x-2)-5(2-3x)=4(2x-6)
4x-2-10+3x=8x-6
4x-3x-8x=-6+2+10
-7x=6
X=6/7



C)5(2x+4)=7(x+1-3)
10x-20=7+x7-3
10x-7x=7-3+26
3x =24
x=24-3
X=21

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Answer 1

Explicação passo a passo:

a

3x + 2 = x + 12

3x - 1x = 12 - 2 ( erro de sinal no exercicio)

2x = 10

x = 10/2 = 5 >>>>>correto

b ( errada)

4 ( x - 2 ) - 5 ( 2 - 3x ) = 4 ( 2x - 6 )

multiplicando os sinais

4x - 8 - 10 + 15x = 8x - 24

4x + 15x - 8x = -24 + 8 + 10

11x = -6

x = -6/11

c

errada

5 ( 2x + 4 ) = 7 ( x + 1 - 3)

reescrevendo

5 ( 2x + 4 ) = 7 ( x - 2 )

[ ( 5 * 2x ) + ( 5 * 4 ) = [ ( 7 * x ) - ( 7 * 2 )]

10x + 20 = 7x - 14

10x - 7x = - 14 - 20

+3x = - 34

x = -34/3 >>>>>resposta