HOC24
Lớp học
Môn học
Chủ đề / Chương
Bài học
bê
1. on
2. at
3. for
4. during
5. with
6. since
7. for
8. on
9. in
10. in
Áp dụng tính chấ dãy tỉ số bằng nhau, ta có:
\(\dfrac{x}{3}=\dfrac{y}{4}=\dfrac{z}{5}=\dfrac{x+y+z}{3+4+5}=\dfrac{2400}{12}=200\\ \\ \\ \\ \\ \\\Rightarrow\left\{{}\begin{matrix}x=200\cdot3=600\\y=200\cdot4=800\\z=200\cdot5=1000\end{matrix}\right.\)
Vậy x=600;y=800;z=1000
Chớp lóe nhay nháy, gà gáy thì mưa.
Trăng đã chiếu sáng vằng vặc, cảnh vật xung quanh thật lung linh, huyền ảo.
Trời nắng chang chang, bác nông dân vẫn đi cấy ngoài đồng.
Would you mind tidying up the classroom when you are finished?
1. yellow
2. helmet
3. fire truck
4. ladder
1. 35
2. 22
3. 67
4. 53
5. 46
6. 99
My friend likes noodles and rice.
1.a) 10=\(\dfrac{40}{4}\)
b) 25= \(\dfrac{100}{4}\)
2.
a) 11=\(\dfrac{11}{1}\)
b) 276=\(\dfrac{276}{1}\)
c) 158=\(\dfrac{158}{1}\)
3.
\(\dfrac{1}{1};\dfrac{2}{2};\dfrac{3}{3};\dfrac{4}{4};\dfrac{5}{5}\)
a)\(\dfrac{\dfrac{2}{5}+\dfrac{2}{7}-\dfrac{2}{9}-\dfrac{2}{11}}{\dfrac{4}{5}+\dfrac{4}{7}-\dfrac{4}{9}-\dfrac{4}{11}}=\dfrac{2\cdot\left(\dfrac{1}{5}+\dfrac{1}{7}-\dfrac{1}{9}-\dfrac{1}{11}\right)}{4\cdot\left(\dfrac{1}{5}+\dfrac{1}{7}-\dfrac{1}{9}-\dfrac{1}{11}\right)}=\dfrac{2}{4}=\dfrac{1}{2}\)
b) \(\dfrac{7.9+14.27+21.36}{21.27+42.81+63.108}=\dfrac{7.9.\left(1+2.3+3.4\right)}{7.9.\left(3.3+6.9+8.12\right)}=\dfrac{1+2.3+3.4}{3.3+6.9+8.12}=\dfrac{1+6+12}{9+54+108}=\dfrac{19}{171}=\dfrac{1}{9}\)