Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
=( 1/12+9/12+2/12+1/12) + ( 2/7+5/7) + (10/20+9/20)
= 13/12 +1+19/20
đến đây bạn tự tính nha
a) \(\frac{3}{5}+\frac{4}{7}+\frac{2}{5}+\frac{1}{7}+\frac{2}{7}\)
\(=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{4}{7}+\frac{1}{7}+\frac{2}{7}\right)\)
\(=\frac{5}{5}+\frac{7}{7}=1+1=2\)
a) \(\frac{3}{5}+\frac{4}{7}+\frac{2}{5}+\frac{1}{7}+\frac{2}{7}\)
\(=\left(\frac{3}{5}+\frac{2}{5}\right)+\left(\frac{4}{7}+\frac{1}{7}+\frac{2}{7}\right)\)
= 1 + 1
= 2
b) \(\frac{4}{9}+\frac{8}{9}+\frac{12}{9}+\frac{16}{9}+...+\frac{48}{9}+\frac{52}{9}+\frac{56}{9}\)
\(=\frac{4+8+12+16+...+48+52+56}{9}\)
Xét 4 + 8 + 12 + 16 + ... + 48 + 52 + 56
Số các số hạng là:
(56 - 4) : 4 + 1 = 14 (số)
4 + 8 + 12 + 16 + ... + 48 + 52 + 56 = (56 + 4) x 14 : 2 = 420
\(\frac{4+8+12+16+...+48+52+56}{9}=\frac{420}{9}=\frac{140}{3}\)
a/ \(\left[\frac{4}{6}+\frac{14}{6}\right]+\left[\frac{7}{13}+\frac{19}{13}\right]+\left[\frac{17}{9}+\frac{1}{9}\right]=\frac{18}{6}+\frac{26}{13}+\frac{18}{9}=3+2+2=7\)
\(\frac{12}{13}-\frac{2}{7}+\frac{8}{13}+\frac{6}{13}-\frac{5}{7}\)
\(=\left(\frac{12}{13}+\frac{8}{13}+\frac{6}{13}\right)-\left(\frac{2}{7}+\frac{5}{7}\right)\)
\(=\frac{26}{13}-\frac{7}{7}\)
\(=2-1\)
\(=1\)
Bài 1 :
12/19 + 4 = 88/19
1234 + 9800 - 9700 = 1334
Bài 2:
10/32 < 9/8
21/14 > 20/12
1)
a)\(\frac{12}{19}\)+4=\(\frac{12}{19}\)+ \(\frac{76}{19}\)=\(\frac{88}{19}\) 1234+9800-9700
=1234+100=1334
2)\(\frac{10}{32}\)<\(\frac{9}{8}\) \(\frac{21}{14}\)<\(\frac{20}{12}\)
(12/7x4/13)+(12/14x14/26)+(6/7x2/13)
= 48/91 + 6/13 + 12/91
= 90/91 + 12/91
= 102/91
\(\dfrac{18}{3}=18:3=6\)
\(\dfrac{45}{9}=45:9=5\)
\(\dfrac{8}{8}=8:8=1\)
\(\dfrac{7}{1}=7:1=7\)
\(\frac{2}{5}=\frac{12}{30}=\frac{40}{100}\)
\(\frac{4}{7}=\frac{12}{21}=\frac{20}{35}\)
nha
anh bn
\(\frac{2}{5}\)\(=\)\(\frac{12}{30}\)\(;\)\(\frac{4}{7}\)\(=\)\(\frac{12}{21}\)\(Done\)
\(\frac{2}{26}\)+\(\frac{9}{12}\)+\(\frac{4}{7}\)+\(\frac{9}{21}\)+\(\frac{12}{13}\)+\(\frac{20}{80}\) = \(\frac{1}{13}+\frac{3}{4}+\frac{4}{7}+\frac{3}{7}+\frac{12}{13}+\frac{1}{4}=\left(\frac{1}{13}+\frac{12}{13}\right)+\left(\frac{4}{7}+\frac{3}{7}\right)+\left(\frac{1}{4}+\frac{3}{4}\right)\)
= 1+ 1+ 1= 3
\(\frac{2}{26}+\frac{9}{12}+\frac{4}{7}+\frac{9}{21}+\frac{12}{13}+\frac{20}{80}\)
=\(\frac{1}{13}+\frac{3}{4}+\frac{4}{7}+\frac{3}{7}+\frac{12}{13}+\frac{1}{4}\)
=\(\left(\frac{1}{13}+\frac{12}{13}\right)+\left(\frac{3}{4}+\frac{1}{4}\right)+\left(\frac{4}{7}+\frac{3}{7}\right)\)
= 1 + 1 + 1
= 3
like nha bạn!!!!