• Matéria: Matemática
  • Autor: vagantesofc2312
  • Perguntado 5 anos atrás

pfv me ajudem, eu tenho que entregar hj!!!!valendo 50 pontos


9) 5x-3x=42

10) 6x-18=4x+8

11) x-5x-2=-18

12) x+5+2x=19+5+2x

13) 3x+20=2(x+3)

14) (5x-4).2=9x+10

15) -8+x=-3

16) x+x=62

17) -(x-1)=-10

18) 3(2x+1)-2(x-3)=0

19)
3x-1
------ =2
4

20)
3ㅤㅤㅤ2x-1
----ㅤㅤ------ㅤ
4ㅤㅤㅤ2



21)
1ㅤㅤㅤ4
-- x + --- x -3 =25
5ㅤㅤㅤ5


22)
1ㅤㅤ 1
-- x + --- x = x +1
2ㅤㅤ4

23)
ㅤx-1ㅤㅤ2x
4- ----- + ---- = 3
ㅤ2ㅤㅤ3

24)
x-1ㅤㅤ5ㅤㅤx
----- + ---- = ---
3ㅤㅤㅤ4ㅤㅤ2


25) 2-8x=x+10

26) x-(5x-3)=2x+(1+x)

27) 3x+1=4

28) 55x+11x=35-24

29)
ㅤㅤ1-xㅤㅤ1
x- -------- + ----- =2x
ㅤㅤ2ㅤㅤㅤ4

30) 3(x-2)=2+2(2+x)​

Respostas

respondido por: edivaldocardoso
1

Resposta:

9)

5x - 3x = 42

2x = 42

x =  \frac{42}{2}  \\  \\  \red{x = 21}

10)

6x - 18 = 4x + 8 \\  \\ 6x - 4x = 8 + 18 \\  \\ 2x = 26 \\  \\ x =  \frac{26}{2}  \\  \\ \red{ x =13}

11)

 x - 5x - 2 =  - 18 \\  \\  - 4x =  - 18 + 2 \\  \\  - 4x =  - 16 \\  \\  - 16 =  - 4x \\  \\ 4x = 16 \\  \\ x =  \frac{16}{4}  \\  \\   \red{x = 4}

12)

x + 5 + 2x = 19 + 5 + 2x \\  \\3 x + 5 = 24 + 2x \\  \\ 3x - 2x = 24 - 5 \\  \\  \red{x = 19}

13)

3x + 20 = 2(x + 3) \\  \\ 3x + 20 = 2x + 6 \\  \\ 3x - 2x = 6 - 20 \\  \\ \red{ x =  - 14}

14)

(5x - 4).2 = 9x + 10 \\  \\ 10x - 8 = 9x + 10 \\  \\ 10x - 9x = 10 + 8 \\  \\  \red{x = 18}

15)

 - 8 + x =  - 3 \\  \\ x =  - 3 + 8 \\  \\ \red{ x = 5}

16)

x + x = 62 \\  \\ 2x = 62 \\  \\ x =  \frac{62}{2}  \\  \\ \red{ x = 31}

17)

 - (x - 1) =  - 10 \\  \\  - x + 1 =  - 10 \\  \\  - x =  - 10 + 1 \\  \\  - x =  -9 \\  \\  - 9 =  -x \\  \\ \red{ x = 9}

18)

3(2x + 1) - 2(x - 3) = 0 \\  \\ 6x + 3 - 2x + 6 = 0 \\  \\ 4x + 9 =  0 \\  \\ 4x =  - 9 \\  \\  \red{x =  -  \frac{9 }{4} }

19)

 \frac{3x - 1}{4}  = 2 \\  \\ 3x - 1 = 4 \times 2 \\  \\ 3x - 1 = 8 \\  \\ 3x = 8 + 1 \\  \\ 3x = 9 \\  \\ x =  \frac{9}{3}  \\  \\  \red{x = 3}

20)

 \frac{3}{4}  =  \frac{2x - 1}{2}  \\  \\ 4(2x - 1) = 3 \times 2 \\  \\ 8x - 4 = 6 \\  \\ 8x = 6 + 4 \\  \\ 8x = 10 \\  \\ x =  \frac{10 \div 2}{8 \div 2}  \\  \\  \red{x =  \dfrac{5}{4} }

21)

 \frac{1x}{5}  +  \frac{4x}{5}  - 3 = 25 \\  \\  \frac{5x}{5}  - 3 = 25 \\  \\ x - 3 = 25 \\  \\ x = 25 + 3 \\  \\  \red{x = 28}

22)

 \frac{1x}{2}  +  \frac{1x}{4}  = x + 1 \\  \\  \frac{4x + 2x = 8x + 8}{8}  \\  \\ 4x + 2x = 8x + 8 \\  \\ 6x = 8x + 8 \\  \\ 8x + 8  = 6x \\  \\ 8x - 6x =   - 8 \\  \\ 2x =  - 8 \\  \\ x =  -  \frac{8}{2}  \\  \\ \red{ x =  - 4}

23)

4 -  \frac{x - 1}{2}  +  \frac{2x}{3}  = 3 \\  \\  \frac{6 \times 4 -3 (x - 1) + 2 \times 2x = 6 \times 3}{6}  \\  \\ 6 \times 4 - 3(x - 1) + 2 \times 2x = 6 \times 3 \\  \\ 24 - 3x + 3 + 4x = 18 \\  \\ x  + 27= 18 \\  \\ x = 18 - 27 \\  \\ \red{ x =  - 9}

24)

 \frac{x - 1}{3}  +  \frac{5}{4}  =  \frac{x}{2}  \\  \\  \frac{4(x - 1) + 3 \times 5 = 6 \times x}{12}  \\  \\ 4(x - 1) + 3 \times 5 = 6 \times x \\  \\ 4x - 4 + 15 = 6x \\  \\ 4x + 11 = 6x \\  \\ 6x   = 4x+ 11 \\  \\ 6x - 4x =  11 \\  \\ 2x = 11 \\  \\  \red{x =  \dfrac{11}{2} }

25)

2 - 8x = x + 10 \\  \\ x  + 10 = 2 - 8x \\  \\  x+ 8x = 2 - 10 \\  \\ 9x =  - 8 \\  \\  \red{x =     - \dfrac{8}{9} }

26)

x - (5x - 3) = 2x + (1 + x) \\  \\ x - 5x + 3 = 2x + 1 + x \\  \\  - 4x + 3 = 3x + 1 \\  \\ 3x + 1 =  - 4x + 3 \\  \\ 3x + 4x = 3 - 1 \\  \\ 7x = 2 \\  \\  \red{x =  \frac{2}{7} }

27)

3x + 1 = 4 \\  \\ 3x = 4 - 1 \\  \\ 3x = 3 \\  \\ x =  \frac{3}{3}  \\  \\  \red{x = 1}

28)

55x + 11x = 35 - 24 \\  \\ 66x = 11 \\  \\ x =  \frac{11 \div 11}{66 \div 11}  \\  \\ \red{ x =  \dfrac{1}{6} }

29)

x -  \frac{1 - x}{2}  +  \frac{1}{4 }  = 2x \\  \\   \frac{8x - 4(1 - x) + 2 \times 1 = 8 \times 2x}{8}  \\  \\ 8x - 4(1 - x) + 2 \times 1 = 8 \times 2x \\  \\ 8x - 4 + 4x  + 2 = 16x \\  \\ 12x - 2 = 16x \\  \\ 16x = 12x - 2 \\  \\ 16x - 12x =  - 2 \\  \\ 4x =  - 2 \\  \\ x =   - \frac{2 \div 2}{4 \div 2}  \\  \\  \red{x =  -  \dfrac{1}{2} }

30)

3(x - 2) = 2 + 2(2 + x) \\  \\ 3x - 6 = 2 + 4 + 2x \\  \\ 3x - 6 = 6 + 2x \\  \\ 3x - 2x = 6 + 6 \\  \\ \red{ x = 12}

Bons Estudos!

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