Chọn B

B

thi tự làm nhé bạn

mik gần thi ;-;

a, Áp dụng t/c dtsbn:

\(\dfrac{a}{b}=\dfrac{c}{d}=\dfrac{a+c}{b+d}\)

b, Áp dụng t/c dtsbn:

\(\dfrac{a}{b}=\dfrac{c}{d}=\dfrac{2021a}{2021b}=\dfrac{2021a-c}{2021b-d}\)

c, Ta có \(\dfrac{a}{b}=\dfrac{c}{d}\Rightarrow\left(\dfrac{a}{b}\right)^2=\left(\dfrac{c}{d}\right)^2\)

Áp dụng t/c dtsbn:

\(\left(\dfrac{a}{b}\right)^2=\left(\dfrac{c}{d}\right)^2=\dfrac{a^2}{b^2}=\dfrac{c^2}{d^2}=\dfrac{a^2+c^2}{b^2+d^2}\)

Anh ơi cho em hỏi dtsbn là gì ạ

A: Oh! Look at that house, it's so beautiful.
B: Yes, It's C's house. It's bigger than my house and yours, too.
C: Hello guys, what are you talking about?
B: We are talking about your house. Uhm...Hey C, How many rooms are there in your house?
C: There are 10 rooms in my house and a big garden behind its.
A: Is it expensive?
C: Yeah, It's nearly 1,5 billions.
A: OMG, your house is more expensive than mine. My house only need about 1 billions to buy it!
B: Your house looks like very convinient.
C: You are right. Do you see our school? It takes me 5 mins to walk to school, so it's the reason why I never late for school.
A: Really? I have many things not as well as you.....
B: It's ok A. You can have it when you learn better than now

Có gì sai sót bạn cứ nói nhé, mình chỉ kịp nghĩ ra đúng đủ 12 câu thôi bạn ạ :)))))

bài j vậy bn

? đề đâu

\(\dfrac{24}{5}\)

\(\dfrac{24}{5}\)

a) (-4,3)+\(\left[\left(-7,5\right)+4,3\right]\)

=\(\left(-4,3\right)+4,3+\left(-7,5\right)\)

=-7,5

b)\(45,3+\left[-7,3+\left(-22\right)\right]\)

=\(45,3-7,3+\left(-22\right)\)

=38-22

=16

c)\(\left[\left(-11,7\right)+5,5\right]+\left[11,7+\left(-2,5\right)\right]\)

=\(\left[\left(-11,7\right)+11,7\right]+5,5-2,5\)

=\(3\)

Thanks you !!

Mik tick rùi nha

B
B

Thanks