tim x biet 3x*(x+1)-x*(3x+2)=6
tim x biet (x-2)^3 -(x-3)(x^2+3x+9)+6(x+1)^2
giup mik voi tim x biet
1, 5-(3x+6)>-2x+1
2, -7.(x+2)-3x<6-11x
3, (x+1).(x+2)-x.(x+3)<4-x
4, 6-2x>17+(4-x)
tim x biet [(3x+8):2]-6=x
tim x biet
|x+1|+|3x+2|=3x
|x-2|+4|x+1|=x-3
tim x biet x^3-3x^2+3x-1=0
x^3 - 3x^2 + 3x - 1 = 0
( x- 1)^3 = 0
=> x -1 = 0
=> x = 1
giup voi
tim x biet
2/3x^2-5x+2 + 13/3x^2+x+2 = 6/x
Tim x,y,z biet (x-1)/2= (y+3)/4 =(z-5)/6 va 5z-3x-4y
Theo đề bài ta có : x−12=y+34=z−56x−12=y+34=z−56 và 5z−3x−4y=505z−3x−4y=50
\Leftrightarrow 3(x−1)6=4(y+3)16=5(z−5)303(x−1)6=4(y+3)16=5(z−5)30 và 5z−3x−4y=505z−3x−4y=50
\Leftrightarrow 3x−36=4y+1216=5z−25303x−36=4y+1216=5z−2530 và 5z−3x−4y=505z−3x−4y=50
Áp dụng tính chất dãy tỉ số bằng nhau ta có :
3x−36=4y+1216=5z−2530=(5z−25)−(3x−3)−(4y+12)30−6−16=5z−3x−4y−25+3−128=168=23x−36=4y+1216=5z−2530=(5z−25)−(3x−3)−(4y+12)30−6−16=5z−3x−4y−25+3−128=168=2
\Rightarrow x−12=2x−12=2 \Rightarrow x−1=4x−1=4 \Leftrightarrow x=5x=5
\Rightarrow y+34=2y+34=2 \Rightarrow y+3=8y+3=8 \Leftrightarrow y=5y=5
\Rightarrow z−56=2z−56=2 \Rightarrow z−5=12z−5=12 \Leftrightarrow z=17z=17
tk nha bạn
tim x biet (2x-2)*(3x+6)=0
\(\left(2x-2\right).\left(3x+6\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}2x-2=0\\3x+6=0\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=2\\3x=-6\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=1\\x=-2\end{cases}}}\)
ĐS: ...........
( 2x - 2 ) . ( 3x + 6 ) = 0
=> 2x - 2 = 0 hoặc 3x + 6 = 0
2x = 0 + 2 hoặc 3x = 0 - 6
2x = 2 hoặc 3x = - 6
x = 1 hoặc x = - 2
*Lưu ý nếu bạn học số nguyên rồi thì mới làm theo cách này nha!
tim x biet /x^2+/3x-1//=x^2+7
|x2+|3x-1||=x2+7
Vì |x2+|3x-1|| \(\ge\) 0;
x2+7 \(\ge\) 0
nên VT=VP
<=>x2+|3x-1|=x2+7
<=>|3x-1|=x2+7-x2=7
<=>\(\int^{3x-1=7\Rightarrow3x=8\Rightarrow x=\frac{8}{3}}_{3x-1=-7\Rightarrow3x=-6\Rightarrow x=-2}\)
Vậy x \(\in\) (-2;8/3}