K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Các câu hỏi dưới đây có thể giống với câu hỏi trên
21 tháng 4 2021
a) Ta có: \(\widehat{xOy}+\widehat{yOz}=180^0\)(hai góc kề bù)
\(\Leftrightarrow\widehat{zOy}+140^0=180^0\)
hay \(\widehat{yOz}=40^0\)
Vậy: \(\widehat{yOz}=40^0\)
NK
17 tháng 4 2023
Mình nghĩ là lần sau bạn tách ra tầm khoảng 4-5 ý rồi đăng thì nó sẽ ngắn hơn ạ;-;. Chứ như này thì dài quá -> không có ai giúp đâu nhé:").
\(a,\dfrac{-6}{13}+\dfrac{7}{-13}=-\dfrac{13}{13}=-1\)
\(b,\dfrac{7}{12}+\dfrac{-9}{24}=\dfrac{14}{24}+\dfrac{-9}{24}=\dfrac{5}{24}\)
\(c,\dfrac{1}{5}+\dfrac{-5}{19}+\dfrac{4}{5}+\dfrac{-14}{19}=\left(\dfrac{1}{5}+\dfrac{4}{5}\right)+\left(\dfrac{-5}{19}+\dfrac{-14}{19}\right)=1+\left(-1\right)=0\)
\(d,\dfrac{5}{13}+\dfrac{-5}{7}+\dfrac{-20}{41}+\dfrac{8}{13}+\dfrac{-21}{41}=\left(\dfrac{5}{13}+\dfrac{8}{13}\right)+\left(\dfrac{-20}{41}+\dfrac{-21}{41}\right)+\dfrac{-5}{7}\)
\(=1+\left(-1\right)+\dfrac{-5}{7}=0+\dfrac{-5}{7}=\dfrac{-5}{7}\)
\(e,\left(8\dfrac{5}{11}+3\dfrac{5}{8}\right)-3\dfrac{5}{11}=\left(\dfrac{93}{11}+\dfrac{29}{8}\right)-\dfrac{38}{11}=\left(\dfrac{93}{11}-\dfrac{38}{11}\right)+\dfrac{29}{8}\)
\(=\dfrac{55}{11}+\dfrac{29}{8}=5+\dfrac{29}{8}=\dfrac{40}{8}+\dfrac{29}{8}=\dfrac{69}{8}\)
\(f,\dfrac{-1}{-5}+\dfrac{8}{7}+\dfrac{-6}{13}-1\dfrac{23}{7}-\dfrac{13}{24}=\dfrac{1}{5}+\dfrac{8}{7}+\dfrac{-6}{13}-\dfrac{30}{7}-\dfrac{13}{24}\)
\(=\dfrac{7}{35}+\dfrac{40}{35}+\dfrac{-6}{13}-\dfrac{30}{7}-\dfrac{13}{24}=\dfrac{47}{35}+\dfrac{-6}{13}-\dfrac{30}{7}-\dfrac{13}{24}\)
\(=\dfrac{611}{455}+\dfrac{-210}{455}-\dfrac{30}{7}-\dfrac{13}{24}=\dfrac{401}{455}-\dfrac{30}{7}-\dfrac{13}{24}=\dfrac{401}{455}-\dfrac{1950}{455}-\dfrac{13}{24}\)
\(=\dfrac{-1549}{455}-\dfrac{13}{24}=\dfrac{-37176}{10920}-\dfrac{5915}{10920}=\dfrac{-43091}{10920}=-3,946\) (số to quá bạn ơi;-;)
\(g,0,75+\dfrac{-1}{3}+\dfrac{3}{6^2}-\dfrac{5}{12}=\dfrac{3}{4}+\dfrac{-1}{3}+\dfrac{3}{36}-\dfrac{5}{12}=\dfrac{9}{12}+\dfrac{-4}{12}+\dfrac{1}{12}-\dfrac{5}{12}\)
\(=\dfrac{9+\left(-4\right)+1-5}{12}=\dfrac{1}{12}\)
\(h,\dfrac{-3}{7}\cdot\dfrac{-1}{9}+\dfrac{-7}{18}\cdot\dfrac{-3}{7}+\dfrac{5}{6}\cdot\dfrac{-3}{7}=\dfrac{-3}{7}\cdot\left(\dfrac{-1}{9}+\dfrac{-7}{18}+\dfrac{5}{6}+1\right)=\dfrac{-3}{7}\cdot\dfrac{4}{3}=\dfrac{-12}{21}\)
\(i,\dfrac{-5}{12}\cdot\dfrac{4}{19}+\dfrac{-7}{12}\cdot\dfrac{4}{19}-\dfrac{40}{57}=\dfrac{4}{19}\cdot\left(\dfrac{-5}{12}+\dfrac{-7}{12}\right)-\dfrac{40}{57}=\dfrac{4}{19}\cdot\left(-1\right)-\dfrac{40}{57}\)
\(=-\dfrac{4}{19}-\dfrac{40}{57}=-\dfrac{12}{57}-\dfrac{40}{57}=-\dfrac{52}{57}\)
\(j,\dfrac{1}{2.3}+\dfrac{1}{3.4}+...+\dfrac{1}{99.100}\)
\(=\dfrac{1}{2}\cdot\dfrac{1}{3}+\dfrac{1}{3}\cdot\dfrac{1}{4}+\dfrac{1}{4}\cdot\dfrac{1}{5}+...+\dfrac{1}{99}\cdot\dfrac{1}{100}\)
\(=\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{99}-\dfrac{1}{100}\)
\(=\dfrac{1}{2}-\dfrac{1}{100}=\dfrac{100}{200}-\dfrac{2}{200}=\dfrac{98}{200}=\dfrac{49}{100}\)
\(k,\dfrac{1}{2.4}+\dfrac{1}{4.6}+...+\dfrac{1}{98.100}\)
\(=\dfrac{1}{2}\cdot\dfrac{1}{4}+\dfrac{1}{4}\cdot\dfrac{1}{6}+...+\dfrac{1}{98}\cdot\dfrac{1}{100}\)
\(=\dfrac{1}{2}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{6}+...+\dfrac{1}{98}-\dfrac{1}{100}\)
\(=\dfrac{1}{2}-\dfrac{1}{100}=\dfrac{100}{200}-\dfrac{2}{200}=\dfrac{98}{100}=\dfrac{49}{100}\)
`@mt`
Hoc24.vn
*Do nhiều ý quá nên bài làm của tớ cũng không tránh khỏi nhầm lẫn, sai sót, có gì bạn tính lại nhé:(, tớ cảm ơn 😭.
17 tháng 4 2023
a: =-6/13-7/13=-13/13=-1
b: =14/24-9/24=5/24
c: =1/5+4/5-5/19-14/19=1-1=0
d: \(=\dfrac{5}{13}+\dfrac{8}{13}-\dfrac{20}{41}-\dfrac{21}{41}-\dfrac{5}{7}=-\dfrac{5}{7}\)
e: \(=8+\dfrac{5}{11}+3+\dfrac{5}{8}-3-\dfrac{5}{11}=8+\dfrac{5}{8}=\dfrac{69}{8}\)
ai giúp mik vs!!!
mik đg cần gấp, giúp mik vs
18 tháng 6 2023
Xét ΔAND và ΔBMC có
AN=BM
ND=MC
AD=BC
=>ΔAND=ΔBMC
=>S vườn=S ABCD=90*70=6300m2
giúp mik vs ạk, mik cần gấp
????
lỗi