Toán Lớp 8: Tìm x biết
a. 3x-2 = 2x – 3
b. 2x+3 = 5x + 9
c. 5-2x = 7
d. 10x + 3 -5x = 4x +12
e. 11x + 42 -2x = 100 -9x -22
f. 2x –(3 -5x) = 4(x+3)
g. x(x+2) = x(x+3)
h. 2(x-3)+5x(x-1) =5×2
Leave a reply
Register Now
Login
Lost Password
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Toán Lớp 8: Tìm x biết
a. 3x-2 = 2x – 3
b. 2x+3 = 5x + 9
c. 5-2x = 7
d. 10x + 3 -5x = 4x +12
e. 11x + 42 -2x = 100 -9x -22
f. 2x –(3 -5x) = 4(x+3)
g. x(x+2) = x(x+3)
h. 2(x-3)+5x(x-1) =5×2
Comments ( 1 )
$b. 2x+3 = 5x + 9$
$<=>-3x=6$
<=>$x=-2$
$c. 5-2x = 7$
$<=>x=-1$
$d. 10x + 3 -5x = 4x +12$
<=>$10x-5x-4x=-3+12$
<=>$x=9$
<=>$11x+9x-2x=-42+100-22$
<=>$18x=36$
<=>$x=2$
$f. 2x –(3 -5x) = 4(x+3)$
<=>$3x=15$
<=>$x=5$
g. $x(x+2) = x(x+3)$
$<=>x^2+2x-x^2-3x=0$
$<=>x=0$
$h. 2(x-3)+5x(x-1) =5x^2$
<=>$2x-6+5x^2-5x-5x^2=0$
<=>$-3x=6$
<=>$x=-2$