B1

A=11x^2-x-2

B=2(-4+x)

B2

a)=(x+3)^2(x-3)

B2

b)=(5x-7)(x+2)

\(\left(4,5-2x\right).1\dfrac{4}{7}+\dfrac{11}{14}\) 

\(=\dfrac{99}{14}-\dfrac{22}{7}x+\dfrac{11}{14}\) 

\(=\left(\dfrac{99}{14}+\dfrac{11}{14}\right)-\dfrac{22}{7}x\) 

\(=\dfrac{55}{7}-\dfrac{22}{7}x\) 
\(=\dfrac{33}{7}+\dfrac{22}{7}.\left(1-x\right)\)

(4,5-2x) * -2=11/14

9/2-2x=11/14:-2

9/2-2x=-11/28

2x=9/2 - (-11/28)

2x=137/28

x=137/28:2

x=137/56

(4,5-2x) * -2=11/14

9/2-2x=11/14:-2

9/2-2x=-11/28

2x=9/2 - (-11/28)

2x=137/28

x=137/28:2

x=137/56

=127/56 nha bn

\(x\times\dfrac{3}{5}=\dfrac{2}{3}+\dfrac{1}{3}\)

\(x\times\dfrac{3}{5}=\dfrac{3}{3}\)

\(x\times\dfrac{3}{5}=1\)

\(x=1:\dfrac{3}{5}\)

\(x=1\times\dfrac{5}{3}\)

\(x=\dfrac{5}{3}\)

\(x-\dfrac{4}{9}=\dfrac{3}{7}:\dfrac{9}{14}\)

\(x-\dfrac{4}{9}=\dfrac{3}{7}\times\dfrac{14}{9}\)

\(x-\dfrac{4}{9}=\dfrac{2}{3}\)

\(x=\dfrac{2}{3}+\dfrac{4}{9}\)

`x`\(=\dfrac{18}{27}+\dfrac{12}{27}\)

\(x=\dfrac{30}{27}=\dfrac{10}{9}\)

Câu 1: Tác phẩm Quốc âm thi tập là của ai ? (1đ)

a. Nguyễn Trãi.

b. Lê Thánh Tông.

c. Lý Tử Tấn.

d .Lương Thế Vinh.

Theo bài ra, ta có:

\(\left(4,5-2x\right).1\dfrac{4}{7}=\dfrac{11}{14}\\ \left(4,5-2x\right).\dfrac{11}{7}=\dfrac{11}{14}\\ 4,5-2x=\dfrac{11}{14}:\dfrac{11}{7}\\ 4,5-2x=\dfrac{1}{2}\\ 2x=4,5-\dfrac{1}{2}\\ \Rightarrow2x=4\\ \Rightarrow x=2\)

Vậy x = 2

\(\left(4,5-2x\right).1\dfrac{4}{7}=\dfrac{11}{14}\)

\(\Leftrightarrow\left(4,5-2x\right).\dfrac{11}{7}=\dfrac{11}{14}\)

\(\Leftrightarrow4,5-2x=\dfrac{11}{14}:\dfrac{11}{7}\)

\(\Leftrightarrow4,5-2x=\dfrac{11}{14}.\dfrac{7}{11}\)

\(\Leftrightarrow4,5-2x=\dfrac{1}{2}\)

\(\Leftrightarrow-2x=\dfrac{1}{2}-4,5\)

\(\Leftrightarrow-2x=-4\)

\(\Leftrightarrow x=2\)

Vậy phương trình có ngiệm x = 2 .

=>4,5-2x=11/14:11/7=1/2

=>2x=4

hay x=2

\(\left(4,5-2x\right)\cdot1\dfrac{4}{7}=\dfrac{11}{14}\)

\(\left(\dfrac{9}{2}-2x\right)\cdot\dfrac{11}{7}=\dfrac{11}{14}\)

\(\dfrac{9}{2}-2x=\dfrac{11}{14}:\dfrac{11}{7}\)

\(\dfrac{9}{2}-2x=\dfrac{1}{2}\)

\(2x=\dfrac{9}{2}-\dfrac{1}{2}\)

\(2x=\dfrac{8}{2}\)

\(x=\dfrac{8}{2}:2\)

`x=2`

bạn nhập rõ hơn đi

4(4,5-2x)=7

18-8x=7

X=11/8

deo hieu

(4,5 - 2\(x\)) (-1\(\dfrac{4}{7}\)) = \(\dfrac{11}{14}\)

(4,5 - 2\(x\)) (-\(\dfrac{11}{7}\)) = \(\dfrac{11}{14}\)

4,5 - 2\(x\) = \(\dfrac{11}{14}\) : ( - \(\dfrac{11}{7}\))

4,5 - 2\(x\) = \(\dfrac{11}{14}\) \(\times\) (- \(\dfrac{7}{11}\))

4,5 - 2\(x\) = - \(\dfrac{1}{2}\) 

4,5 - 2\(x\) = -0,5

2\(x\) = 4,5 + 0,5

2\(x\) = 5

\(x\) = 5: 2

\(x\) = 2,5 

tham khảo

cái này đúng không nhỉ 

\(\Leftrightarrow4,5-2x=\dfrac{11}{14}:\dfrac{11}{7}\)

\(\Leftrightarrow4,5-2x=\dfrac{1}{2}\)

\(\Leftrightarrow2x=4,5-\dfrac{1}{2}\)

\(\Leftrightarrow x=4:2\)

\(\Leftrightarrow x=2\)

4,5 -2x = 11/14 : 1 4/7

4,5 -2x = 11/14 : 11/7

4,5 -2x =  1/2

2x = 4,5 - 1/2

2x = 4

x = 4 : 2

x = 2

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