so sanh \(\frac{29}{33},\frac{22}{37},\frac{29}{37}\)
so sánh phân số ;
a)\(\frac{29}{33};\frac{22}{37};\frac{29}{37}\)b)
\(\frac{22}{37}\) < \(\frac{29}{37}\) < \(\frac{29}{33}\)
Ghi nhớ : Muốn so sánh phân số , ta lấy tử chia cho mẫu
\(\frac{22}{37}\)< \(\frac{29}{37}\)<\(\frac{29}{33}\)
so sanh
â) 1256/1257 và 18/17 b) 213/215 và 317/319 c) 29/33 ; 22/37; 29/37 d) 1111/3333 và 4nhan9tru 4 nhân 6/8 nhân 5 công 4 nhan2
ai trả lời thì mình sẽ k ngay cho người đó
So sánh \(A=\frac{20}{39}+\frac{22}{27}+\frac{18}{43}\)và \(B=\frac{14}{37}+\frac{22}{29}+\frac{18}{41}\)
Áp dụng bất đẳng thức : \(\frac{a}{b}< 1\Rightarrow\frac{a}{b}< \frac{a+n}{b+n}\)
Ta chứng minh được \(\frac{20}{39}>\frac{18}{41};\frac{18}{43}>\frac{14}{39};\frac{22}{27}>\frac{22}{29}\)
\(\Rightarrow\frac{20}{39}+\frac{22}{27}+\frac{18}{43}>\frac{14}{37}+\frac{22}{29}+\frac{18}{41}\)
\(\Rightarrow A>B\)
\(\left(4\frac{5}{37}-3\frac{4}{5}+8\frac{15}{29}\right)-\left(3\frac{5}{37}-6\frac{14}{29}\right)\)
\(\left(4\frac{5}{37}-3\frac{4}{5}+8\frac{15}{29}\right)-\left(3\frac{5}{37}-6\frac{14}{29}\right)\)
tinh gia tri bieu thuc sau
\(\frac{15-\frac{5}{17}-\frac{5}{29}-\frac{5}{37}}{5-\frac{5}{17}-\frac{5}{29}-\frac{5}{37}}\)
(5/17-5/17)-(5/29-5/29)-(5/37-5/37)-(15-5)=0-0-0-10=-10
Cho A = \(\frac{1}{17}+\frac{1}{19}+\frac{1}{25}+\frac{1}{27}+\frac{1}{29}+\frac{1}{33}+\frac{1}{35}+\frac{1}{37}+\frac{1}{39}\)
Tính nhanh : \(\frac{4}{3}+\frac{7}{6}+\frac{11}{10}+\frac{16}{15}+\frac{22}{21}+\frac{29}{28}+\frac{37}{36}+\frac{46}{45}\)
=(1+1+1+1+1+1+1+1)+(1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45)
Đặt A = 1/3+1/6+1/10+1/15+1/21+1/28+1/36+1/45
Ta có:
A x 1/2= 1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90
1/6=1/2x3=1/2-1/3
1/12=1/3x4=1/3-1/4
……………………
1/90=1/9x10=1/9-1/10
A x 1/2=1/2-1/3+1/3-1/4+1/4-1/5+…+1/9-1/10
A x 1/2=1/2-1/10=4/10
A=4/10:1/2=4/5
Vậy 4/3+7/6+11/10+16/15+22/21+29/28+37/36+46/45=1+1+1+1+1+1+1+1+4/5=8+4/5=44/5
\(\frac{4}{3}+\frac{7}{6}+\frac{11}{10}+...+\frac{46}{45}\)
\(=1+\frac{1}{3}+1+\frac{1}{6}+1+\frac{1}{10}+...+1+\frac{1}{45}\)
\(=\left(1+1+1+...+1\right)+\left(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{45}\right)\)(8 chữ số 1)
\(=8+\left(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{45}\right)\)
Đặt A = \(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{45}\)
=> \(\frac{1}{2}\)A = \(\frac{1}{2}\times\left(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{45}\right)\)
= \(\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{90}\)
\(=\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{9.10}\)
\(=\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{9}-\frac{1}{10}\)
\(=\frac{1}{2}-\frac{1}{10}=\frac{2}{5}\)
Vậy A = \(\frac{2}{5}:\frac{1}{2}=\frac{4}{5}\)
Do đó biểu thức trên là 8 + \(\frac{4}{5}\) = \(\frac{44}{5}\)
Đáp số: \(\frac{44}{5}\)
hic hic, Việt , mình đồng cảm với bạn
mình đánh chữ chậm như rùa
So sánh phân số
29/33 ; 22/37 ; 29/37163/257 ; 163/221 ; 149/257
1. \(\frac{29}{33}>\frac{29}{37}>\frac{22}{37}\)
2.\(\frac{163}{221}>\frac{163}{257}>\frac{149}{257}\)