Question

2. Qual equação de 1° grau tem resposta igual a 21?
A) 5(2x - 1) = 2(x + 4)
B) 2x + 1 + 5(x - 3) = 3(x + 1) + X
C) 10 - 2(x + 3) = 8 + 3(2x + 5)
D) 10x - 5 (1 + x) = 3 (2x - 2) - 20
E) 3x - 7 + 2(x - 1) = 2x - 3​

Answer 1

resposta : D

Explicação passo-a-passo:

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

10x-5=2x+8

10x-2x= 8+5

8x=13

x=13/8

B) 2x + 1 + 5(x - 3) = 3(x + 1) + X

2x+1+5x-15=3x+3+x

2x+5x-3x-x= 3-1+15

3x=17

x=17/3

C) 10 - 2(x + 3) = 8 + 3(2x + 5)

10-2x-6=8+6x+15

-2x-6x=8+15-10+6

-8x=19

x=19/-8

D) 10x - 5 (1 + x) = 3 (2x - 2) - 20

10x-5-5x=6x-6-20

10x-5x-6x= -6-20+5

-x= -21 (-1)

x=21

E) 3x - 7 + 2(x - 1) = 2x - 3

3x-7+2x-2=2x-3

3x+2x-2x=-3+7+2

3x=12

x=12/3

x=4