Tìm x biết rằng:
a) ( x 2 + 2x + 4)(2 - x) + x(x - 3)(x + 4) - x 2 + 24 = 0;
b) x 2 + 3 ( 5 − 6 x ) + ( 12 x − 2 ) x 4 + 3 = 0 .
Tìm x, biết:
a, (x-3)^2-4=0
b, x^2-2x=24
c,(2x-1)^2+(x+3)^2-5(x+7)(x-7)=0
b/ x2-2x=24
=> x2-2x-24=0
=> (x-6)(x+4)=0
=>x=6 hoặc x =-4
a/ (x-3)2 - 4 = 0
=> (x-3-2)(x-3+2)=0
=> (x-5)(x-1)=0
=> x = 5 hoặc x=1
tìm x biết
( x2 + 2x + 4 ) * ( 2 - x ) + x( x - 3 ) * ( x + 4 ) - x2 + 24 = 0
\(=>2^3-x^3+\left(x^2-3x\right)\left(x+4\right)-x^2+24=0\)
\(=>8-x^3+x^3+x^2-12x-x^2+24=0\)
\(=>-12x=-16=>x=\frac{4}{3}\)
Vậy \(x=\frac{4}{3}\)
\(\left(x^2+2x+4\right)\left(2-x\right)+x\left(x-3\right)\left(x+4\right)-x^2+24=0\)
\(\Leftrightarrow2x^2-x^3+4x-2x^2+8-4x+\left(x^2-3x\right)\left(x+4\right)-x^2+24=0\)
\(\Leftrightarrow2x^2-x^3+4x-2x^2+8-4x+x^3+4x^2-3x^2-12x-x^2+24=0\)
\(\Leftrightarrow-12x+8+24=0\)
\(\Leftrightarrow-12x+32=0\)
\(\Leftrightarrow-12x=-32\)
\(\Leftrightarrow x=\frac{8}{3}\)
Tìm x, biết
a) 5x-3{4x-2[4x-3(5x-2)]}=182
b)(x2+2x+4).(2-x)+x.(x-3).(x+4)-x2+24=0
#)Giải :
a)\(5x-3\left\{4x-2\left[4x-3\left(5x-2\right)\right]\right\}\)
\(\Leftrightarrow5x-3\left[4x-2\left(4x-15x+6\right)\right]\)
\(\Leftrightarrow5x-3\left(4x-8x+30x-12\right)\)
\(\Leftrightarrow5x-12x+24x-90x+36\)
\(\Leftrightarrow-73x+36=182\)
\(\Leftrightarrow-73x=146\)
\(\Leftrightarrow x=-2\)
tìm x
x^3 -2x^2+x-2=0
2x(3x-5)=10-6x
4-x=2(x-4)^2
4-6x+x(3x-2)=0
\(x^3-2x^2+x-2=0\\ \Leftrightarrow x^2\left(x-2\right)+\left(x-2\right)=0\\ \Leftrightarrow\left(x^2+1\right)\left(x-2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x^2+1=0\\x-2=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x^2=-1\left(vô.lí\right)\\x=2\end{matrix}\right.\\ Vậy:x=2\\ ---\\ 2x\left(3x-5\right)=10-6x\\ \Leftrightarrow6x^2-10x-10+6x=0\\ \Leftrightarrow6x^2-4x-10=0\\ \Leftrightarrow6x^2+6x-10x-10=0\\ \Leftrightarrow6x\left(x+1\right)-10\left(x+1\right)=0\\ \Leftrightarrow\left(6x-10\right)\left(x+1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}6x-10=0\\x+1=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{3}\\x=-1\end{matrix}\right.\)
\(4-x=2\left(x-4\right)^2\\ \Leftrightarrow4-x=2\left(x^2-8x+16\right)\\ \Leftrightarrow2x^2-16x+32+x-4=0\\ \Leftrightarrow2x^2-15x+28=0\\ \Leftrightarrow2x^2-8x-7x+28=0\\ \Leftrightarrow2x\left(x-4\right)-7\left(x-4\right)=0\\ \Leftrightarrow\left(2x-7\right)\left(x-4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}2x-7=0\\x-4=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{2}\\x=4\end{matrix}\right.\\ ---\\ 4-6x+x\left(3x-2\right)=0\\ \Leftrightarrow4-6x+3x^2-2x=0\\ \Leftrightarrow3x^2-8x+4=0\\ \Leftrightarrow3x^2-6x-2x+4=0\\ \Leftrightarrow3x\left(x-2\right)-2\left(x-2\right)=0\\ \Leftrightarrow\left(3x-2\right)\left(x-2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}3x-2=0\\x-2=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{3}\\x=2\end{matrix}\right.\)
bài 9:tìm x
1) (x-3)^2-4=0
2) x^2-2x=24
3) (2x-1)^2+(x+3)^3-5(x+7)(x-7)=0
giúp mình với mn ơi
1) \(\left(x-3\right)^2-4=0\)
\(\Leftrightarrow\left(x-3-2\right)\left(x-3+2\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=1\end{matrix}\right.\)
2) \(x^2-2x=24\)
\(\Leftrightarrow x^2-2x-24=0\)
\(\Leftrightarrow x^2+4x-6x-24=0\)
\(\Leftrightarrow x\left(x+4\right)-6\left(x+4\right)=0\)
\(\Leftrightarrow\left(x+4\right)\left(x-6\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-4\end{matrix}\right.\)
tìm x
a(2x+1)(x-4)=(2x+1)^2
b(x-4)(x^2+4x-16)-(x^2-6)=2
c( 2x-1)^2-(3x+4)^2=0
d(9x+2)(x-1)-(3x-1)^2=0
e(2x+3)^2-4(x-1)(x-1)(x+1)=0
f)15x(x+4-6x-24=0
g)(4-10x)(2-3x)-30^2=0
giải giùm mik nha các bn :3
bạn đăng tách ra nhé
a, \(\left(2x+1\right)\left(x-4\right)=\left(2x+1\right)^2\)
\(\Leftrightarrow2x^2-7x-4=4x^2+4x+1\Leftrightarrow2x^2+11x+5=0\)
\(\Leftrightarrow\left(x+5\right)\left(2x+1\right)=0\Leftrightarrow x=-5;x=-\frac{1}{2}\)
b, sửa đề : \(\left(x-4\right)\left(x^2+4x+16\right)-\left(x^2-6\right)=2\)
\(\Leftrightarrow x^3-64-x^2+6=2\Leftrightarrow x^3-x^2-60=0\Leftrightarrow x=4,27...\)
c, \(\left(2x-1\right)^2-\left(3x+4\right)^2=0\Leftrightarrow\left(2x-1+3x+4\right)\left(2x-1-3x-4\right)=0\)
\(\Leftrightarrow\left(5x+3\right)\left(-x-5\right)=0\Leftrightarrow x=-\frac{3}{5};x=-5\)
d, \(\left(9x+2\right)\left(x-1\right)-\left(3x-1\right)^2=0\)
\(\Leftrightarrow9x^2-7x-2-9x^2+6x-1=0\Leftrightarrow-x-3=0\Leftrightarrow x=-3\)
e, \(\left(2x+3\right)^2-4\left(x-1\right)\left(x-1\right)\left(x+1\right)=0\)
\(\Leftrightarrow4x^2+12x+9-4\left(x-1\right)\left(x^2-1\right)=0\)
\(\Leftrightarrow4x^2+12x+9-4\left(x^3-x-x^2+1\right)=0\)
\(\Leftrightarrow4x^2+12x+9-4x^3+4x+4x^2-4=0\)
\(\Leftrightarrow-4x^3+8x^2+16x+5=0\Leftrightarrow x=-0,9...;x=-0,41...;x=3,31...\)
f, \(15x\left(x+4-6x-24\right)=0\Leftrightarrow15\left(-5x-20\right)=0\)
\(\Leftrightarrow-75x-300=0\Leftrightarrow x=-4\)
g, \(\left(4x-10\right)\left(2-3x\right)-30^2=0\)
\(\Leftrightarrow8x-12x^2-20+30x-900=0\Leftrightarrow-12x^2+38x-920=0\)
vô nghiệm
Tìm x biết rằng:(x2+2x+4) (2-x)+x(x-3) (x+4)-x2+24=0
Tìm x, biết
a, (x-3)^2 -4 =0
b, x^2 -2x =24
c, (2x-1) ^2 + (x+3)^2 -5 .(x+7).(x-7) =0
Ai làm nhanh và đầy đủ mình sẽ tick cho nha !
a) \(\left(x-3\right)^2-4=0\)
\(\left(x-7\right)\left(x+1\right)=0\)
\(\orbr{\begin{cases}x=7\\x=-1\end{cases}}\)
b) \(x^2-2x=24\)
\(x^2-2x-24=0\)
\(\left(x-6\right)\left(x+4\right)=0\)
\(\orbr{\begin{cases}x=6\\x=-4\end{cases}}\)
c) \(\left(2x-1\right)^2+\left(x+3\right)^2-5\left(x+7\right)\left(x-7\right)=0\)
\(4x^2+4x+1+x^2+6x+9-5\left(x^2-49\right)=0\)
\(5x^2+10x+10-5x^2+245=0\)
\(10x+255=0\)
\(x=-25.5\)
A) \(\left(x-3\right)^2-4=0\)
\(\left(x-3\right)^2=4\Rightarrow\left(x-3\right)^2=\left(-2\right)^2;2^2\)
th1\(\left(x-3\right)^2=2^2\)
\(\Rightarrow x-3=2\)
\(\Rightarrow x=2+3\)
\(\Rightarrow x=5\)
th2: \(\left(x-3\right)^2=\left(-2\right)^2\)
\(\Rightarrow x-3=-2\)
\(\Rightarrow x=-2+3\)
\(\Rightarrow x=1\)
\(\Leftrightarrow x\in\left\{1;5\right\}\)
a) \(\left(x-3\right)^2-4=0\)
Ta xét 2TH:
TH1: \(x-3=2\)
\(x-3+3=2+3\)
\(x=5\)
TH2: \(x-3=-2\)
\(x-3+3=-2+3\)
\(x=1\)
=> \(x\in\left\{1;5\right\}\)
Tìm x biết a) x(x-25)=0 b)2x(x-4)-x(2x-1)=-28 c)x^2 -5x=0 d)(x-2)^2-(x+1)(x+3)=-7 e)(3x+5).(4-3x)=0 f)x^2-1/4=0
a: \(x\in\left\{0;25\right\}\)
c: \(x\in\left\{0;5\right\}\)