x : 6,25 = 15,8
X x 16 = 86,4
X x34 = 266 ,22
x - 319,76 = 439 + 315,61
\(^{x^4-6x^3+16x^2-22x+16=0}\) chứng minh pt sau vô nghiệm.
\(x^4-6x^3+16x^2-22x+16=0\)
\(\Rightarrow x^4-2x^3+3x^2-4x^3+8x^2-12x+5x^2-10x+15+1=0\)
\(\Rightarrow x^2\left(x^2-2x+3\right)-4x\left(x^2-2x+3\right)+5\left(x^2-2x+3\right)x^2+1=0\)
\(\Rightarrow\left(x^2-2x+3\right)\left(x^2-4x+5\right)=-1\)
\(\Rightarrow\left(x^2-2x+1+2\right)\left(x^2-4x+4+1\right)=-1\)
\(\Rightarrow\left[\left(x-1\right)^2+2\right]\left[\left(x-2\right)^2+1\right]=-1\left(1\right)\)
mà \(\left\{{}\begin{matrix}\left(x-1\right)^2+2>0,\forall x\\\left(x-2\right)^2+1>0,\forall x\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\left[\left(x-1\right)^2+2\right]\left[\left(x-2\right)^2+1\right]>0,\forall x\\\left[\left(x-1\right)^2+2\right]\left[\left(x-2\right)^2+1\right]=-1\end{matrix}\right.\) (vô lí)
Vậy phương trình trên vô nghiệm (dpcm)
tìm x
5)
4x x 5 x 4x 3 5
6)
2
2
x 2 x 1 6
7)
2
3
(3 2) 3 .
4
x x x
8) (3x + 1). (2x- 3) – 6x.(x + 2) = 16
8: =>6x^2-9x+2x-3-6x^2-12x=16
=>-19x=19
=>x=-1
xét tính chẵn lẻ của hàm số
a)\(y=f\left(x\right)=\sin^22x+cos3x\)
b)\(y=f\left(x\right)=cos\sqrt{x^2-16}\)
a, \(f\left(-x\right)=sin^2\left(-2x\right)+cos\left(-3x\right)=sin^22x+cos3x=f\left(x\right)\)
\(\Rightarrow\) Là hàm số chẵn.
b, \(f\left(-x\right)=\sqrt{\left(-x\right)^2-16}=\sqrt{x^2-16}=f\left(x\right)\)
\(\Rightarrow\) Là hàm số chẵn.
Tìm số nguyên x, biết:
a) 1 6 = x 18
b) x 8 = − 1 4
c) 4 − 5 = x 10
d) 11 5 = − 22 x
e) x 8 = 8 x
f) x − 11 = − 11 x
a) x = 3
b) x = -2
c) x= -8
d) x = -10
e) x= 8 hoặc x = -8
f) x = 11 hoặc x = -11
4x5x6x 7 x…… x34/6x7x8x9x…. x 32
Phân tích đa thức thành nhân tử
1) (x^2-11x+30).(x^2+22x+120)-3x^2
2) (x-1)^4+(x-3)^4-16
25 / 24x 27 /5 x 2 x34 /9 x 36 /17
\(\dfrac{25}{24}\times\dfrac{27}{5}\times2\times\dfrac{34}{9}\times\dfrac{36}{17}\)
\(=(\dfrac{25}{24}\times\dfrac{54}{5})\times\left(\dfrac{34}{9}\times\dfrac{36}{17}\right)\)
\(=\dfrac{45}{4}\times2\times4\)
\(=90\)
16 x34 =
mn kết bn nha
16 x 34 = 544
đáp số : 544
kết bn vs mk nhé tk luôn !
cảm ơn bn nhìu , love là 0
= 544
chuk bn may mắn
tìm x ∈ Z biết
a ) 4(x - 1) - ( 3x + 2 ) = 16
b) 7(x - 5 ) + 5(15 - x ) = 130
c) 30 . (x- 2 ) - 6( x - 5 ) - 22x = 100
d) x - 17 + x = x - 23
a)
\(4\left(x-1\right)-\left(3x+2\right)=16\)
=> 4x - 4 - 3x - 2 = 16
=> x - 6 = 16
=> x = 22
Vậy .......
b)
\(7\left(x-5\right)+5\left(15-x\right)=130\)
=> 7x - 35 + 75 - 5x = 130
=> 2x + 40 = 130
=> 2x = 90
=> x = 45
Vậy........
c)
\(30\left(x-2\right)-6\left(x-5\right)-22x=100\)
=> 30x - 60 - 6x + 30 - 22x = 100
=> 2x - 30 = 100
=> 2x = 130
=> x = 65
Vậy.....
d) \(x-17+x=x-23\)
=> 2x - 17 = x - 23
=> x = -6
Vậy .......
a) 4(x-1)-(3x+2)=16 b)7(x-5)+5(15-x)=130
<=>4x-4-3x-2=16 <=>7x-35+75-5x=130
<=>x-6=16 <=>2x+40=130
<=>x=22 <=>2x=90
<=>x=45
c) 30(x- 2 ) - 6( x - 5 ) - 22x = 100 d) x-17+x=x-23
<=>30x-60-6x+30-22x=100 <=>2x-x=-23+17
<=>2x-30=100 <=>x=-6
<=>2x=130
<=>x=65
a) 4(x-1)-(3x+2)=16
<=>4x-4-3x-2=16
<=>x-6=16
<=>x=22
c) 30(x- 2 ) - 6( x - 5 ) - 22x = 100
<=>30x-60-6x+30-22x=100
<=>2x-30=100
<=>2x=130
<=>x=65
b)7(x-5)+5(15-x)=130
<=>7x-35+75-5x=130
<=>2x+40=130
<=>2x=90
<=>x=45
d) x-17+x=x-23
<=>2x-x=-23+17
<=>x=-6
<=>2x=130
<=>x=65