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NV
6 tháng 4 2019

\(x\ne\left\{3;4;5;6\right\}\)

\(\frac{3}{x-3}-\frac{5}{x-5}=\frac{4}{x-4}-\frac{6}{x-6}\)

\(\Leftrightarrow\frac{3}{x-3}+1-\frac{5}{x-5}-1=\frac{4}{x-4}+1-\frac{6}{x-6}+1\)

\(\Leftrightarrow\frac{x}{x-3}-\frac{x}{x-5}=\frac{x}{x-4}-\frac{x}{x-6}\)

\(\Leftrightarrow x\left(\frac{1}{x-3}+\frac{1}{x-6}-\frac{1}{x-4}-\frac{1}{x-5}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\\frac{1}{x-3}+\frac{1}{x-6}=\frac{1}{x-4}+\frac{1}{x-5}\left(1\right)\end{matrix}\right.\)

\(\left(1\right)\Leftrightarrow\frac{2x-9}{\left(x-3\right)\left(x-6\right)}=\frac{2x-9}{\left(x-4\right)\left(x-5\right)}\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-9=0\\\left(x-3\right)\left(x-6\right)=\left(x-4\right)\left(x-5\right)\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{9}{2}\\18=20\left(l\right)\end{matrix}\right.\)

\(\Rightarrow\overline{x}=\frac{\frac{9}{2}+0}{2}=\frac{9}{4}\)

13 tháng 8 2015

Gợi ý vàng 

1. Giải quyết cho x: - 1/2 × | 2x + 6 | + 2 = 0
A. x = 5 hoặc x = 1
B. x = 5
C. x = -5 hoặc x = -1
D. x = -1
E. x = -6

13 tháng 8 2015

1) -1/2. |2x + 6| + 2 = 0 

<=> 1/2. |2x+6| = 2 <=> |2x+6| = 4 <=> 2x+6 = 4 or  2x + 6 = -4

+) 2x + 6 = 4 <=> x = -1

+) 2x+6 = -4 <=> x = -5

Answer: C

2/ E. 

 

22 tháng 6 2020

Take it easy:

2 X 2 = 42 with 4 = 2 X 2 and 2 = 2 X 2 - 2

2 X 4 = 86 with 8 = 2 X 4 and 6 = 2 X 4 - 2

6 X 3 = 1812 with 18 = 6 X 3 and 12 = 6 X 3 - 6

...

So 7 X 2 = 147 with 14 = 7 X 2 and 7 = 7 X 2 - 7

22 tháng 6 2020

7 X 2 = 14

Lesson 1: analyzing the polynomial factors.Notes + 2 x-1x 3 + 6x2 + 11x + 6x 4 + 2 x 2-3AB + ac + b2 + 2bc + c2A3-b3 + c3 + 3abcLesson 2: for functions: search conditions of x to A means.A shortening.Computer x to A < 1.Post 3: prove the inequality:For a + b + c = 0. Prove that: a3 + b3 + c3 = 3abc.For a, b, c are the sidelengths of the triangle. Proof that:Prove that x 5 + y5 ≥ x4y + xy4 with x, y ≠ 0 and x + y ≥ 0Lesson 4: solve the equation:x 2-3 x + 2 + | x-1 | = 0Lesson 5: find the...
Đọc tiếp

Lesson 1: analyzing the polynomial factors.

Notes + 2 x-1
x 3 + 6x2 + 11x + 6
x 4 + 2 x 2-3
AB + ac + b2 + 2bc + c2
A3-b3 + c3 + 3abc
Lesson 2: for functions: 

search conditions of x to A means.
A shortening.
Computer x to A < 1.
Post 3: prove the inequality:

For a + b + c = 0. Prove that: a3 + b3 + c3 = 3abc.
For a, b, c are the sidelengths of the triangle. Proof that:


Prove that x 5 + y5 ≥ x4y + xy4 with x, y ≠ 0 and x + y ≥ 0
Lesson 4: solve the equation:

x 2-3 x + 2 + | x-1 | = 0


Lesson 5: find the largest and smallest value (if any)

A = x 2-2 x + 5
B =-2 x 2-4 x + 1.
C = 
Lesson 6: calculate the value of expression.

Know a – b = 7 feature: A = (a + 1) a2-b2 (b-1) + ab-3ab (a-b + 1)
For three numbers a, b, c is not zero catches up deals for equality: 
Computer: P = 

Article 7: proof that

8351634 + 8241142 divisible 26.
A = n3 + 6n2-19n-24 divisible by 6.
B = (10n-9n-1) divisible 27 with n in N *.
Article 8:

In the motorcycle race three cars depart at once. The second car in a one-hour run slower than the first car 15 km and 3 km third cars. rapidly should the destination more slowly the first car 12 minutes and the third car earlier today. No stops along the way. Calculate the speed of each car, race distance and the time each car

0
1 tháng 3 2018

Hinh câu 1

12 tháng 4 2017

Thay x=1 vào pt, ta có: \(\left(a+1\right)\left(b+1\right)\left(c+1\right)=-5\left(1\right)\)

vì vai trò của a,b,c là như nhau, giả sử:\(a>b>c\Rightarrow a+1>b+1>c+1\left(2\right)\)

vì a,b,c là số nguyên nên a+1,b+1,c+1 cũng là số nguyên (3)

từ (1),(2),(3)\(\Rightarrow\hept{\begin{cases}a+1=5\\b+1=1\\c+1=-1\end{cases}\Leftrightarrow\hept{\begin{cases}a=4\\b=0\\c=-2\end{cases}}}\)

17 tháng 1 2018

x2+xy+y2=x2y2

=> x2+2xy+y2=x2y2-xy

=> (x+y)2=xy(xy+1)

Vi (x+y)2 chinh phuong , nen xy(xy+1) cung chinh phuong

Vay xy=xy+1 hoac xy=0

TH1 xy=xy+1 => 0=1 ( vo ly)

TH2 xy=0 => xy(xy+1)=0 => x+y=0 => x=y=0