giúp mình làm bài với :
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
b: \(=8+2\cdot3-7\cdot1.3+3\cdot\dfrac{5}{4}=8.65\)
Today, I will tell you some things to make school greener-cleaner. Firstly, I will ask everyone not to throw rubbish in the school because it is the reason of air pollution. Secondly, I will advise everyone to plant trees and flowers in the school yard. Thirdly, I will ask my teacher to celebrate many activities to protect the environment. Finnaly, I will advise everyone not to damage trees and flowers.... If everyone try to protect the environment, the school will be greener.
- plant some trees
- don't throw trash on the street
- plant some flowers
- don't damage trees
- don't pick flowers
Mẫu ví dụ của mình. Chúc bạn học tốt !
Bài 5:
Ta có : \(\widehat{A_1}+\widehat{A_3}=180^o\) (kề bù)
\(100^o+\widehat{A_3}=180^o\)
\(\widehat{A_3}=80^o\)
Ta có: \(\widehat{A_3}=\widehat{B_1}=80^o\)
\(\widehat{A_3}\) và \(\widehat{B_1}\) ở vị trí đồng vị
\(\Rightarrow AC//BD\)
\(\Rightarrow\widehat{C}_1=\widehat{D_1}=135^o\) (đồng vị)
\(x=135^o\)
b)
Ta có: \(\widehat{G_1}+\widehat{B_1}=180^o\left(120^o+60^o=180^o\right)\)
\(\widehat{G_1}\) và \(\widehat{B_1}\) ở vị trí trong cùng phía
\(\Rightarrow QH//BK\)
\(\Rightarrow\widehat{H_1}=\widehat{K_1}=90^o\)(so le)
\(x=90^o\)
\(\text{Δ}=\left(-3\right)^2-4\cdot\left(2m+1\right)\)
=9-8m-4=-8m+5
Để phương trình có nghiệm kép thì -8m+5=0
hay m=5/8
Pt trở thành \(x^2-3x+\dfrac{9}{4}=0\)
hay x=3/2
Bài 1:
Vì (d)//y=-2x+1 nên a=-2
Vậy: y=-2x+b
Thay x=1 và y=2 vào (d),ta được:
b-2=2
hay b=4
Bài 1:
\(a,\dfrac{-3}{5}+\dfrac{11}{10}=\dfrac{-6}{10}+\dfrac{11}{10}=\dfrac{5}{10}=\dfrac{1}{2}\\ b,\dfrac{-6}{20}+\dfrac{-11}{22}=\dfrac{-3}{10}-\dfrac{1}{2}=\dfrac{-3}{10}-\dfrac{5}{10}=\dfrac{-8}{10}=\dfrac{-4}{5}\\ c,\dfrac{7}{14}-\dfrac{-3}{6}=\dfrac{1}{2}+\dfrac{1}{2}=\dfrac{2}{2}=1\\ d,5-\dfrac{-2}{3}=\dfrac{15}{3}+\dfrac{2}{3}=\dfrac{17}{3}\\ e,-11+\dfrac{3}{7}=\dfrac{-77}{7}+\dfrac{3}{7}=\dfrac{-74}{7}\\ g,-6-\dfrac{7}{25}=\dfrac{-150}{25}-\dfrac{7}{25}=\dfrac{-157}{25}\)
Bài 2:
\(A=\dfrac{-11}{2022}+\dfrac{19}{1999}+\dfrac{11}{2022}+\dfrac{18}{1999}\)
\(\Rightarrow A=\left(\dfrac{-11}{2022}+\dfrac{11}{2022}\right)+\left(\dfrac{19}{1999}+\dfrac{18}{1999}\right)\)
\(\Rightarrow A=0+\dfrac{37}{1999}\)
\(\Rightarrow A=\dfrac{37}{1999}\)
chăm chỉ