- Giúp mk vs
Tìm x
( x + 3/4 ) ^2 - 9/16 = 0
Giúp mk bài này vs mk cảm ơn nhìu
Tìm x : (X^2-9).(x^2+16)<0 và ((X^2-9).(x^2+16)>0
Giúp mk vs tìm x
1/ (x-1)3+3x(x-1)=0
2/ x^2 -25=6x-9
3/ 4x^2-1-x(2x+1)=0
4/ (4x-1)^2-9=0
\(\left(x-1\right)3+3x\left(x-1\right)=0\)
<=> \(3\left(x-1\right)\left(x+1\right)=0\)
<=> \(\orbr{\begin{cases}x-1=0\\x+1=0\end{cases}}\)
<=> \(\orbr{\begin{cases}x=1\\x=-1\end{cases}}\)
Vậy...
Tìm x biết
a) \(\left(x-4\right)^2-36=0\)
b)\(\left(x+8\right)^2=121\)
c)\(x^2+8x+16=0\)
d)\(4x^2-12x+9=0\)
GIÚP MK VS MK ĐG CẦN GẤP AI NHANH MK TICK CHO
a/ \(\left(x-4\right)^2-36=0\)
<=> \(\left(x-4-6\right)\left(x-4+6\right)=0\)
<=> \(\left(x-10\right)\left(x+2\right)=0\)
<=> \(\orbr{\begin{cases}x-10=0\\x+2=0\end{cases}}\)<=> \(\orbr{\begin{cases}x=10\\x=-2\end{cases}}\)
b/ \(\left(x+8\right)^2=121\)
<=> \(\left(x+8\right)^2-121=0\)
<=> \(\left(x+8-11\right)\left(x+8+11\right)=0\)
<=> \(\left(x-3\right)\left(x+19\right)=0\)
<=> \(\orbr{\begin{cases}x-3=0\\x+19=0\end{cases}}\)<=> \(\orbr{\begin{cases}x=3\\x=-19\end{cases}}\)
d/ \(4x^2-12x+9=0\)
<=> \(\left(2x\right)^2-2.2x.3+3^2=0\)
<=> \(\left(2x-3\right)^2=0\)
<=> \(2x-3=0\)
<=> \(x=\frac{3}{2}\)
\(c,x^2+8x+16=0\)
\(\Rightarrow x^2+4x+4x+16=0\)
\(\Rightarrow x.\left(x+4\right)+4.\left(x+4\right)=0\)
\(\Rightarrow\left(x+4\right)^2=0\)
\(\Rightarrow x=-4\)
\(d,4x^2-12x+9=0\)
\(4x^2-6x-6x+9=0\)
\(\Rightarrow\left(2.2x^2-2.3x\right)-\left(3.2x-3^2\right)=0\)
\(\Rightarrow2.\left(2x^2-3x\right)-3.\left(2x-3\right)=0\)
\(\Rightarrow2x.\left(2x-3\right)-3.\left(2x-3\right)=0\)
\(\Rightarrow\left(2x-3\right)^2=0\)
\(\Rightarrow2x-3=0\Rightarrow x=1,5\)
Hai phần đầu dễ bãn tự làm
\(1,\)
\(2x\left(x-3\right)-\left(3-x\right)=0\)
\(\Leftrightarrow2x\left(x-3\right)+\left(x-3\right)=0\)
\(\Leftrightarrow\left(2x+1\right)\left(x-3\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}2x+1=0\\x-3=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{-1}{2}\\x=3\end{cases}}\)
\(2,\)
\(3x\left(x+5\right)-6\left(x+5\right)=0\)
\(\Leftrightarrow\left(3x-6\right)\left(x+5\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}3x-6=0\\x+5=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=2\\x=-5\end{cases}}\)
\(3,\)
\(x^4-x^2=0\)
\(\Leftrightarrow x^2\left(x^2-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x^2=0\\x^2-1=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=\pm1\end{cases}}\)
\(4,\)
\(x^2-2x=0\)
\(\Leftrightarrow x\left(x-2\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x-2=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=2\end{cases}}\)
\(5,\)
\(x\left(x+6\right)-10\left(x-6\right)=0\)
\(\Leftrightarrow x^2+6x-10x+60=0\)
\(\Leftrightarrow x^2-4x+60=0\)
\(\Leftrightarrow x^2-4x+4+56=0\)
\(\Leftrightarrow\left(x-2\right)^2=-56\)(Vô lý)
=> Phương trình vô nghiệm
(2) giải pt: \(\sqrt{x^2-16}-2\sqrt{x+4}=0\)
giúp mk vs ạ, mai mk hc rồi
\(\Leftrightarrow\sqrt{x+4}\left(\sqrt{x-4}-2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+4=0\\x-4=4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-4\\x=8\end{matrix}\right.\)
Tìm x thuộc N biết .19. (2+3+4-5+6-7)^2-9.(7.x-2)=0 giải giúp mk nhanh nhanh vs ạ.
19.9-63x+18=0
-63x= -(171+18)
-63x= -189
x=189:63
x=3
bài 3:tìm x,biết:(giúp mk vs mk cần gấp)
a)14/15 : 9/10 = x : 3/7
b)(x- 4/7)^3= 343
c)x^5 = x^3
d)x^13 = 27x^10
e)(x-1)^4 = 16
a) \(\frac{14}{15}:\frac{9}{10}=x:\frac{3}{7}\Rightarrow\frac{28}{27}=x:\frac{3}{7}\Rightarrow x=\frac{4}{9}\)
b) \(\left(x-\frac{4}{7}\right)^3=343\Rightarrow\left(x-\frac{4}{7}\right)^3=7^3\Rightarrow x-\frac{4}{7}=7\Rightarrow x=\frac{53}{7}\)
c) \(x^5=x^3\Leftrightarrow\hept{\begin{cases}x=1\\x=0\end{cases}}\)
e) \(\left(x-1\right)^4=16\Leftrightarrow\orbr{\begin{cases}\left(x-1\right)^4=2^4\\\left(x-1\right)^4=\left(-2\right)^4\end{cases}}\)\(\Leftrightarrow\orbr{\begin{cases}x-1=2\\x-1=\left(-2\right)\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=3\\x=-1\end{cases}}\)
tìm x: (3x-1)^2-16=0. m.n giúp mk vs nha:)))
(3x - 1 )2 - 16 =0
<=>(3x - 1 )2 = 16
<=>3x-1 =4
<=>x=5/3
(3x - 1)2 - 16 = 0
<=> (3x - 1)2 - 42 = 0
<=> (3x - 1 - 4)(3x - 1 + 4) = 0
<=> (3x - 5)(3x + 3) = 0
<=> 3x - 5 = 0 hoặc 3x + 3 = 0
<=> x = 5/3 hoặc x = - 1
(3x-1)^2-16=0
(3x-1)^2=16
Th1: 3x-1=4
3x=5
x=5/3
Th2: 3x-1=-4
3x=-3
x=-1
Tìm x:x³-9/16*x=0 giupa mk vs ạ mk cần gấp
=>x(x^2-9/16)=0
=>x(x-3/4)(x+3/4)=0
=>x=0; x=3/4; x=-3/4