
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.


a)\(\frac{19}{20}+\frac{1}{20}=1\)
\(\frac{20}{21}+\frac{1}{21}=1\)
vi \(\frac{1}{20}>\frac{1}{21}\) nen \(\frac{19}{20}<\frac{20}{21}\)
b) \(\frac{89}{88}-\frac{1}{88}=1\)
\(\frac{90}{89}-\frac{1}{89}=1\)
vi \(\frac{1}{88}>\frac{1}{89}nen\frac{89}{88}>\frac{90}{89}\)
c)\(\frac{2005}{2003}-\frac{2}{2003}=1\)
\(\frac{2003}{2001}-\frac{2}{2001}=1\)
vi \(\frac{2}{2003}<\frac{2}{2001}nen\frac{2005}{2003}<\frac{2003}{2001}\)

Ta có \(x.a=b\)
\(x=b:a\)
Do đó \(-\frac{3}{5}.x=\frac{5}{6}\)
\(x=\frac{5}{6}:\frac{-3}{5}\)
\(x=-\frac{1}{2}\)
Tương tự
2. \(x=\frac{6}{8}:\frac{2}{4}=\frac{3}{2}\)
Bạn tự làm câu 3
1.\(\frac{-3}{5}\).x=\(\frac{5}{6}\)
x=\(\frac{5}{6}\):\(\frac{-3}{5}\)
x=\(\frac{-25}{18}\)
2.\(\frac{2}{4}\):x=\(\frac{6}{8}\)
\(\frac{1}{2}\):x=\(\frac{3}{4}\)
x=\(\frac{1}{2}\):\(\frac{3}{4}\)
x=\(\frac{2}{3}\)
3.\(\frac{67}{89}\).x=\(\frac{12}{13}\)
x=\(\frac{12}{13}\):\(\frac{67}{89}\)
x=\(\frac{1068}{871}\)
K MIK NHÉ

so sánh với 1
rút gọn hoặc quy đồng số còn lại để so sánh tử
so sánh với 1
cũng so sánh với 1
bạn đùa hay hỏi thật vậy

a) Ta có :\(\frac{12}{18}< \frac{12}{17}\)
Mà : \(\frac{12}{17}< \frac{13}{17}\)
Từ đó : \(\frac{12}{18}< \frac{13}{17}\)

\(\left(2.8x-32\right):\frac{2}{3}=90\)
\(2.8\cdot x-32=90\cdot\frac{2}{3}\)
\(\frac{14}{5}x-32=60\)
\(\frac{14}{5}x=60+32\)
\(\frac{14}{5}x=92\)
\(x=\frac{230}{7}\)
B , c , d tương tự

a) Ta thấy : 4/5 < 1 ; 15/14 > 1
nên 4/5 < 15/14
b) Ta thấy : 89/88 > 1 ; 100/101 < 1
nên 89/88 > 100/101
c) Ta có : 300/901 < 300/900 = 1/3
nên 300/901 < 1/3
d) Ta có : 5/10 = 1/2 = 1000/2000
Ta thấy 1000/2000 < 1001/2000
nên 5/10 < 1001/2000

Tính A rồi so sánh:
\(\frac{1}{4}\) + \(\frac{1}{9}\) + \(\frac{1}{16}\) + \(\frac{1}{25}\) + \(\frac{1}{36}\) = \(\frac{1769}{3600}\)
3600 chia hết cho 6, nên ta chọn 3600 làm mẫu số chung.
3600 : 6 = 600
\(\frac{5}{6}\) = \(\frac{5\times600}{6\times600}\) = \(\frac{3000}{3600}\)
Mà \(\frac{3000}{3600}\) > \(\frac{1769}{3600}\)
Nên: \(\frac{5}{6}\) > A

1)
a)15/90 = 1/6, 120/600=1/5, 75/150=1/5 mau so chung=30
1/6=5/30
1/5=6/30
1/5=6/30
b)54/90=3/5, 180/288=5/8, 60/135=4/9
3/5=3*8*9/5*8*9=216/360
5/8=5*5*9/5*8*9=225/360
4/9=4*8*5/5*8*9=160/360
bai 2 ban tu lam di,mk met roi
\(\frac{46}{87}< \frac{67}{90}\)
Ta có:
\(\frac{46}{49}=\frac{46x90}{89x90}=\frac{4140}{8010}\)
\(\frac{67}{90}=\frac{67x89}{90x89}=\frac{5963}{8010}\)
Vậy: \(\frac{4140}{8010}< \frac{5963}{8010}\)