1. What are they doing?
2. What Loan look like?
3. What does your sister like?
4. What's Lisa wearing now?
5. Why does she never go fishing?

Bài 2:
a, Ta có: \(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{5}=\dfrac{x+y+z}{2+3+5}=\dfrac{30}{10}=3\)
* \(\dfrac{x}{2}=3\Rightarrow x=6\)
* \(\dfrac{y}{3}=3\Rightarrow y=9\)
* \(\dfrac{z}{5}=3\Rightarrow z=15\)
b, Ta có: \(\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{5}=\dfrac{2y}{6}=\dfrac{3z}{15}=\dfrac{x-2y+3z}{2-6+15}=\dfrac{22}{11}=2\)
* \(\dfrac{x}{2}=2\Rightarrow x=4\)
* tương tự như tìm x để tính y, z nhé.
 

THAM KHẢO:
https://vndoc.com/tap-lam-van-lop-3-ke-lai-buoi-dau-em-di-hoc-131551

:)))

B.
 \(=\left(3^4\right)^3:3^5=3^{12}:3^5=3^7\)

a, 48
b, -240
c, 1200
Mấy câu này bấm máy tính á