tìm xEZ biết
a 6x+8= 2x-12
b 12-x=x+1
c 14+4x=3x+20
d 2.(x-1)+ 3.(x-2)= x-4
e 3.(4-x)- 2.(x-1)= x+20
f 2.(x-3)-3.(x-5)= 4.(3-x)-1
tìm xEZ biết
a 6x+8= 2x-12
b 12-x=x+1
c 14+4x=3x+20
d 2.(x-1)+ 3.(x-2)= x-4
e 3.(4-x)- 2.(x-1)= x+20
f 2.(x-3)-3.(x-5)= 4.(3-x)-1
$a, 6x + 8 = 2x – 12$
$6x – 2x = -12 – 8$
$4x = -20$
$x = -5$
$Vậy x = -5$
$b, 12 – x = x + 1$
$-x – x = 1 – 12$
$-2x = -11$
$x =$ `11/2`
$Vậy x =$ `11/2`
$c, 14 + 4x = 3x + 20$
$4x – 3x = 20 – 14$
$x = 6$
$Vậy x = 6$
$d, 2 ( x – 1 ) + 3 ( x – 2 ) = x – 4$
$2x – 2 + 3x – 6 = x – 4$
$5x – 8 = x – 4$
$5x – x = – 4 + 8$
$4x = 4$
$x = 1$
$Vậy x = 1$
$e, 3 ( 4 – x ) – 2 ( x – 1 ) = x + 20$
$12 – 3x – 2x + 2 = x + 20$
$14 – 5x = x + 20$
$-5x – x = 20 – 14$
$-6x = 6$
$x = -1$
$Vậy x = -1$
$f, 2 ( x – 3 ) – 3 ( x – 5 ) = 4 ( 3 – x ) – 1$
$2x – 6 – 3x + 15 = 12 – 4x – 1$
$-x + 9 = 11 – 4x$
$-x + 4x = 11 – 9$
$3x = 2$
$x =$ `2/3`
$Vậy x =$ `2/3`
a) ${ 6x+8= 2x-12}$
⇒ ${ 6x-2x = -12-8}$
⇒ ${ 4x = -20}$
⇒ ${ x = -5}$
b) ${ 12-x=x+1}$
⇒ ${ -x -x = 1-12 }$
⇒ ${ -2x = -11}$
⇒ ${ x = \frac{11}{2}}$
c) ${ 14+4x=3x+20}$
⇒ ${ 4x-3x = 20-14}$
⇒ ${ x = 6}$
d) ${ 2.(x-1)+ 3.(x-2)= x-4}$
⇒ ${ 2x-2+3x-6=x-4}$
⇒ ${ 2x+3x-x = -4+2+6}$
⇒ ${ 4x = 4}$
⇒ ${ x=1}$
e) ${ 3.(4-x)- 2.(x-1)= x+20}$
⇒ ${ 12-3x-2x+2=x+20}$
⇒ ${ -3x-2x-x = 20-12-2}$
⇒ ${ -6x = 6}$
⇒ ${ x =-1}$
f) ${2.(x-3)-3.(x-5)= 4.(3-x)-1}$
⇒ ${ 2x-6-3x+15=12-4x-1}$
⇒ ${ 2x-3x+4x = 12-1+6-15}$
⇒ ${3x=2}$
⇒ ${ x =\frac{2}{3}}$