d. 2x²(x - y) + 2y(y - x)

= 2x²(x - y) - 2y(x - y)

= (2x² - 2y)(x - y)

= 2(x² - y)(x - y)

e. 5a²b(a - 2b) - 2a(2b - a)

= 5a²b(a - 2b) + 2a(a - 2b)

= (5a²b + 2a)(a - 2b)

= a(5ab + 2)(a - 2b)

f. 4x²y(x - y) + 9xy²(x - y)

= (4x²y + 9xy²)(x - y)

= xy(4x + 9y)(x - y)

g. 50x²(x - y)² - 8y²(y - x)²

= 50x²(x² - 2xy + y²) - 8y²(y² - 2xy + x²)

= 50x²(x² - 2xy + y²) - 8y²(x² - 2xy + y²)

= 50x²(x - y)² - 8y²(x - y)²

= (50x² - 8y²)(x - y)²

= 2(25x² - 4y²)(x - y)².

g: Ta có: \(50x^2\left(x-y\right)^2-8y^2\left(y-x\right)^2\)

\(=2\left(x-y\right)^2\left(25x^2-4y^2\right)\)

\(=2\left(x-y\right)^2\left(5x-2y\right)\left(5x+2y\right)\)

\(tana=\sqrt{3}\)

=>\(\dfrac{sina}{cosa}=\sqrt{3}\)

=>\(sina=\sqrt{3}\cdot cosa\)

\(1+tan^2a=\dfrac{1}{cos^2a}\)

=>\(\dfrac{1}{cos^2a}=1+3=4\)

=>\(cos^2a=\dfrac{1}{4}\)

=>\(cosa=\dfrac{1}{2}\)

=>\(sina=\dfrac{\sqrt{3}}{2}\)

\(A=\dfrac{sin^2a-cos^2a}{sina\cdot cosa}\)

\(=\dfrac{\dfrac{3}{4}-\dfrac{1}{4}}{\dfrac{\sqrt{3}}{2}\cdot\dfrac{1}{2}}=\dfrac{2}{4}:\dfrac{\sqrt{3}}{4}=\dfrac{2}{\sqrt{3}}=\dfrac{2\sqrt{3}}{3}\)

hữu danh vô thực

Hữu danh vô thực

Hữa danh vô thực .

#Songminhnguyệt

4 Can you tell me the way to the museum?

5 Her family is going to visit Huong in Can Tho this summer

6 How far is it from your house to Quynh coi Primary school?

7 In VN the new school year begins on September the fifth 

My family went to Da Lat by coach

Can you tell me the way to the museum?

Huong is going to visit her family in Can Tho by train this summer.

How far is it from your house to primary school?

The school year in Vietnam begins on the fifth September.

my family went to Da Lat by coach

can you tell me the way to the museum?

huong is going to visit her family in Can Tho by train this summer.

how far is it from your house to primary school?

the school year in Vietnam begins on the fifth September. 

tick nhé

Tuổi thanh thiếu niên . Là tạp chí yêu thích của tôi.

Tuổi thanh thiếu niên. Đó là tạp chí yêu thích của tôi

Tuổi thanh thiếu niên . Là tạp chí yêu thích của tôi

Vì a.b=0 => a hoặc b phải bằng 0.

TH1: a=0

=> 2a+3b=14 -> 2.0+3b=14

                           0+3b=14

                                b=4,666  (loại)

TH2: b=0

=> 2a+3b=14 -> 2a+3.0=14

                            2a+0=14

                             a=7 (chọn)

Vậy a=7, b=0

Because a,b could be positive and negative numbers include zero, we seem that a = 7, b = 0

bn phải cho A = ...................... chứ !

C1: How much are your shoes?

C2: How much do you shoes cost?

Mình lộn nhé, cách 2 là How much do your shoes cost

a) i2=i3-i1=0,35-0,2=0,15A

b) U1=U2=12V do mắc song song 

c) Tớ không chắc lắm nhưng tớ nghĩ là có vì dây dẫn vẫn cho dòng đi qua