Tìm x
5-(6 - x ) = 4× ( 3 - 2x )
Tìm số tự nhiên x, biết:
a) ( x + 1 ) 4 = ( 2 x ) 4 ;
b) ( 2 x - 1 ) 5 = x 5
a) Ta có: ( x + 1 ) 4 = ( 2 x ) 4 nên x +1 = 2x. Do đó x = 1.
b) Ta có: ( 2 x - l ) 5 = x 5 nên 2x - l = x. Do đó x = l.
Cho 2 đa thức
f(x)=-x5+6x3+8x2+12x+x5+\(\dfrac{2}{3}+2x^{4^{ }}+\dfrac{1}{3}\)
g(x)=2x4+6x3+17x2+12x-26
1. Thu gọn và sắp xếp f(x) theo lũy thừa giảm của biến
2. Tính h(x)=f(x)-g(x)
2. Tìm nghiệm h(x)
1.
\(f\left(x\right)=2x^4+6x^3+8x^2+12x+1\)
2.
\(h\left(x\right)=\left(2x^4+6x^3+8x^2+12x+1\right)-\left(2x^4+6x^3+17x^2+12x-26\right)\)
\(=-9x^2+27\)
3.
\(h\left(x\right)=0\Leftrightarrow-9x^2+27=0\)
\(\Leftrightarrow x^2=3\Rightarrow x=\pm\sqrt{3}\)
tìm x:
x3-x2=0
3x2-5x=0
x3=x5
(2x+7)2-4(2x+7)=0
a)x3-x2=0
⇔x2(x-1)=0
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)
b)3x2-5x=0
⇔ x(3x-5)=0
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{5}{3}\end{matrix}\right.\)
c)x3=x5
⇔ x3(1-x2)=0
⇔ x3(1-x)(1+x)=0
⇔\(\left[{}\begin{matrix}x=0\\x=1\\x=-1\end{matrix}\right.\)
d)(2x+7)2-4(2x+7)=0
⇔ (2x+7)(2x+3)=0
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-7}{2}\\x=\dfrac{-3}{2}\end{matrix}\right.\)
a) Ta có: \(x^3-x^2=0\)
\(\Leftrightarrow x^2\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\)
b) Ta có: \(3x^2-5x=0\)
\(\Leftrightarrow x\left(3x-5\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{5}{3}\end{matrix}\right.\)
c) Ta có: \(x^3=x^5\)
\(\Leftrightarrow x^5-x^3=0\)
\(\Leftrightarrow x^3\left(x^2-1\right)=0\)
\(\Leftrightarrow x^3\left(x-1\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=1\\x=-1\end{matrix}\right.\)
d) Ta có: \(\left(2x+7\right)^2-4\left(2x+7\right)=0\)
\(\Leftrightarrow\left(2x+7\right)\left(2x+3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-7}{2}\\x=\dfrac{-3}{2}\end{matrix}\right.\)
Tìm nghiệm của đa thức:
M(x)=x3-25x
M(x)=x5+27x2
G(x)=(x2+2)(-2x+4)
cho M(x) =0
\(=>x^3-25x=0=>x\left(x^2-25\right)=0\)
\(=>\left[{}\begin{matrix}x=0\\x^2-25=0\end{matrix}\right.=>\left[{}\begin{matrix}x=0\\x^2=25=>\left[{}\begin{matrix}x=5\\x=-5\end{matrix}\right.\end{matrix}\right.\)
M(x) =0
\(=>x^5+27x^2=0=>x^2\left(x^3+27\right)=0\)
\(=>\left[{}\begin{matrix}x^2=0\\x^3=-27\end{matrix}\right.=>\left[{}\begin{matrix}x=0\\x=-3\end{matrix}\right.\)
Tìm x
5/12:I x+0,125 I = 7/24
5/12.I x-4/9I=0,75
I5/6+xI:4/5=3/8
I75%-xI.5/9=7/18
c: Ta có: \(\left|x+\dfrac{5}{6}\right|:\dfrac{4}{5}=\dfrac{3}{8}\)
\(\Leftrightarrow\left|x+\dfrac{5}{6}\right|=\dfrac{3}{8}\cdot\dfrac{4}{5}=\dfrac{3}{10}\)
\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{5}{6}=\dfrac{3}{10}\\x+\dfrac{5}{6}=-\dfrac{3}{10}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{-8}{15}\\x=-\dfrac{17}{15}\end{matrix}\right.\)
TÌM Y BIẾT:
a) y x 4/3= 16/9
b) (y-1/2)+0,5=3/4
c) 4/5-2/5 x y=0,2
d) (y+3/4)x5/7=10/9
e) y : 5/4=9/5+1/2
f) y x 1/2+3/2x y=4/5
a, y \(\times\) \(\dfrac{4}{3}\) = \(\dfrac{16}{9}\)
y = \(\dfrac{16}{9}\) : \(\dfrac{4}{3}\)
y = \(\dfrac{4}{3}\)
b, ( y - \(\dfrac{1}{2}\)) + 0,5 = \(\dfrac{3}{4}\)
y - 0,5 + 0,5 = \(\dfrac{3}{4}\)
y = \(\dfrac{3}{4}\)
c, \(\dfrac{4}{5}-\dfrac{2}{5}y\) = 0,2
0,8 - 0,4y = 0,2
0,4y = 0,8 - 0,2
0,4y = 0,6
y = 1,5
d, (y + \(\dfrac{3}{4}\)) \(\times\) \(\dfrac{5}{7}\) = \(\dfrac{10}{9}\)
y + \(\dfrac{3}{4}\) = \(\dfrac{10}{9}\) : \(\dfrac{5}{7}\)
y + \(\dfrac{3}{4}\) = \(\dfrac{14}{9}\)
y = \(\dfrac{14}{9}\) - \(\dfrac{3}{4}\)
y = \(\dfrac{29}{36}\)
e, y : \(\dfrac{5}{4}\) = \(\dfrac{9}{5}\) + \(\dfrac{1}{2}\)
y : \(\dfrac{5}{4}\) = \(\dfrac{23}{10}\)
y = \(\dfrac{23}{10}\)
y = \(\dfrac{23}{8}\)
f, y \(\times\) \(\dfrac{1}{2}\) + \(\dfrac{3}{2}\) \(\times\) y = \(\dfrac{4}{5}\)
y \(\times\) ( \(\dfrac{1}{2}+\dfrac{3}{2}\)) = \(\dfrac{4}{5}\)
2y = \(\dfrac{4}{5}\)
y = \(\dfrac{2}{5}\)
1.Viết dưới dạng lũy thừa
a/2.3.2.3.2.3
b/100.100.100
c/2x.2x.2x
d/2.23.25
e/310.35.34
2/Tìm x
a/40-x=26.22
b/32.3x=81
c/2x=512
d/x5=243
3/tính
36=
83=
33.75+3325=
d/23.3-(110+8):3=
e/32-[4+(5.32 - 42)] -14
giúp mình zới
Bài 1:
a) \(2\cdot3\cdot2\cdot3\cdot2\cdot3=2^3\cdot3^3=6^3\)
b) \(100\cdot100\cdot100=100^3=\left(10^2\right)^3=10^6\)
c) \(2x\cdot2x\cdot2x=\left(2x\right)^3=8x^3\)
d) \(2\cdot2^3\cdot2^5=2^{1+3+5}=2^9\)
e) \(3^{10}\cdot3^5\cdot3^4=3^{10+5+4}=3^{19}\)
Bài 2:
\(40-x=2^6\cdot2^2\)
\(\Rightarrow40-x=2^8\)
\(\Rightarrow40-x=256\)
\(\Rightarrow x=40-256\)
\(\Rightarrow x=-216\)
b) \(3^2\cdot3^x=81\)
\(\Rightarrow3^{2+x}=3^4\)
\(\Rightarrow2+x=4\)
\(\Rightarrow x=4-2=2\)
c) \(2^x=512\)
\(\Rightarrow2^x=2^9\)
\(\Rightarrow x=9\)
d) \(x^5=243\)
\(\Rightarrow x^5=3^5\)
\(\Rightarrow x=3\)
Bài 3:
a) \(3^6=3\cdot3\cdot3\cdot3\cdot3\cdot3=729\)
b) \(8^3=\left(2^3\right)^3=2^9=512\)
c) \(3^3\cdot75+3^3\cdot25=3^3\cdot\left(75+25\right)=3^3\cdot100=27\cdot100=2700\)
d) \(2^3\cdot3-\left(1^{10}+8\right):3=2^3\cdot3-9:3=2^3\cdot3-3\cdot3:3=3\cdot\left(2^3-3:3\right)=3\cdot\left(8-1\right)=21\)
e) \(32-\left[4+\left(5\cdot3^2-42\right)\right]-14=18-\left[4+\left(45-42\right)\right]\)
\(=18-\left(4+3\right)\)
\(=18-7=11\)
2:
a: =>40-x=256
=>x=40-256=-216
b: =>x+2=4
=>x=2
c: =>2^x=2^9
=>x=9
d; =>x^5=3^5
=>x=3
Bài 2: Cho hai đa thức: a(x) = x5- 2x3+ 3x4 - 9x2+11x -6
b(x) = 3x4+ x5 - 2(x3 + 4 ) - 10x2 + 9x
a. Tính c(x) = a(x)- b(x)
b. Tìm x để c(x) = 2x+2
c. Chứng tỏ rằng c(x) không thể nhận thêm giá trị bằng 2012 với mọi x∈Z.
Tính tổng
A=1 x 5 x 51 x52 x 53x54x55x56x57x58x59x510
kết quả là 5 ^ 56
tìm a ?
a x5 +a=360 :6
720 :[a x2 +a x3 ]= 2x 3
câu 1 giống các bn ấy nhưng ko bít cách làm
720 : ( a * 2 + a * 3 ) = 2 * 3
720 : ( a * 5 ) = 6
720 : 6 : 5
= 120 : 5
a = 24