J'aimerais Savoir Si J'ai Bon A Des Equations !...

[minnellea]

bonjour,

est ce que vous pouvez me dire si j'ai bon a ces quelque équations ? ou m'aidez ? SVP

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

6-15x+3+x-1-2x=5x+7

-15x+x-2x-5x = -6-3+1+7

-21= -1

x= -1/ -21 s:{1/21}

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

3-7x-1+x = 2x+2

-7x +x -2x = -3 +1+2

-8=0 s:{0}

c)22x+7x-2x+2x= 10-1+6+18

29x = 33

x = 33/29

d) 2-[1+x-(5-7x)]= 2x-1+3(1-x)

2-1-x-5+7x = 2x-1+3-3x

-x+7x-2x-3x = -2+1+5-1+3

1=6

e) (11-x)/84 + (x-5)/4 - (2x-1)/12 + 7/3 =0

=(11-x)/84 +21(x-5)/84 - 7(2x-1)84 + 7*28/84=0

10x+21x-105-14x-7+196=0

10x+21x= -105-7+196

31x = 84

f) x+7*1/3 + 1-2*7x/2= 7/6 - 1*2x-5/3

g)3(2-x)+2x²-5 = x+2(x+3)²

6 - 3x + 2x² - 5 = x + 2(x² + 6x + 9)

6 - 3x + 2x² - 5 = x + 2x² + 12x + 18

-3x + 2x² - x - 2x² - 12x = -6 + 5 + 18

-16x = 17

-x = 17/13

x = -17/16

h) 2(3x-1)-4(1+x) = 8-2(1+2x)

6x - 2 - 4 - 4x = 8 - 2 - 4x

2x - 6 = 6 - 4x

2x + 4x = 6 + 6

6x = 12

x = 12/6

x = 2

x= 84/31

x=6/1 s:{6}

merci d'avance !

[Barbidoux]

bonjour,

est ce que vous pouvez me dire si j'ai bon a ces quelque équations ? ou m'aidez ? SVP

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

6-15x+3+x-1-2x=5x+7

-15x+x-2x-5x = -6-3+1+7

-21= -1

x= -1/ -21 s:{1/21}

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

3-7x-1+x = 2x+2

-7x +x -2x = -3 +1+2

-8=0 s:{0}

c)22x+7x-2x+2x= 10-1+6+18

29x = 33

x = 33/29

d) 2-[1+x-(5-7x)]= 2x-1+3(1-x)

2-1-x+5-7x -2x+1-3+3x=0

4-7x=0

s:{4/7}

e) (11-x)/84 + (x-5)/4 - (2x-1)/12 + 7/3 =0

(11-x)/84 +21(x-5)/84 - 7(2x-1)84 + 7*28/84=0

11-x+21*x-105-14*x+7+196=0

109-6*x=0

s:{109/6}

f) x+7*1/3 + 1-2*7x/2= 7/6 - 1*2x-5/3

6*x/6+14/6+6/6-42*x/6-7/6+12*x/6+10/6=0

6*x+14+6-42*x-7+12*x+10=0

23-24*x=0

s:{23/24}

g)3(2-x)+2x²-5 = x+2(x+3)²

6 - 3x + 2x² - 5 = x + 2(x² + 6x + 9)

6 - 3x + 2x² - 5 = x + 2x² + 12x + 18

-3x + 2x² - x - 2x² - 12x = -6 + 5 + 18

-16x = 17

-x = 17/13

x = -17/16

h) 2(3x-1)-4(1+x) = 8-2(1+2x)

6x - 2 - 4 - 4x = 8 - 2 - 4x

2x - 6 = 6 - 4x

2x + 4x = 6 + 6

6x = 12

x = 12/6

x = 2

s:{2}

x= 84/31

x=6/1 s:{6} ???

merci d'avance !