Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
12/14 + 15/20 + 6/7 + 3/4
= ( 12/14 + 6/7 ) + ( 15/20 + 3/4 )
= ( 6/7 + 6/7 ) + ( 3/4 + 3/4 )
= 12/7 + 6/4
= 48/28 + 42/28
= 90/28
= 45/14
Tham khảo nha !!!
a, \(\frac{6}{7}.\frac{16}{15}.\frac{7}{6}.\frac{21}{32}=\frac{6}{7}.\frac{7}{6}.\frac{16}{15}.\frac{21}{32}\)=\(1.\frac{16}{15}.\frac{21}{32}=\frac{7}{5.2}=\frac{7}{10}\)
Phần b T2
c,\(\frac{7}{4}.\frac{11}{21}+\frac{11}{21}.\frac{5}{4}=\frac{11}{21}.\left(\frac{7}{4}+\frac{5}{4}\right)\)=\(\frac{11}{21}.3=\frac{11}{7}\)
\(\left(2.8x-32\right):\frac{2}{3}=90\)
\(2.8\cdot x-32=90\cdot\frac{2}{3}\)
\(\frac{14}{5}x-32=60\)
\(\frac{14}{5}x=60+32\)
\(\frac{14}{5}x=92\)
\(x=\frac{230}{7}\)
B , c , d tương tự
=(5/9+20/18)+(2/7+6/14)
=(5/9+10/9)+(2/7+3/7)
=15/9+5/7
=50/21
a, \(\frac{3}{4}\times\frac{4}{7}+\frac{5}{14}\)
\(=\frac{3}{7}+\frac{5}{14}=\frac{6}{14}+\frac{5}{14}=\frac{11}{14}\)
b, \(\frac{5}{14}+\frac{9}{7}\div\frac{3}{4}\)
\(=\frac{5}{14}+\frac{9}{7}\times\frac{4}{3}=\frac{5}{14}+\frac{12}{7}=\frac{5}{14}+\frac{24}{14}=\frac{29}{14}\)
c, \(\frac{12}{17}\div x=\frac{3}{5}\)
\(x=\frac{12}{17}\div\frac{3}{5}=\frac{12}{17}\times\frac{5}{3}=\frac{20}{17}\)
\(\frac{3}{4}X\frac{4}{7}+\frac{5}{14}\)
\(=\frac{3}{7}+\frac{5}{14}\)
\(=\frac{6}{14}+\frac{5}{14}\)
\(=\frac{11}{14}\)
so sánh
a,\(\frac{6}{7}...\frac{12}{14}\)
\(\frac{6}{7}=\frac{6.2}{7.2}=\frac{12}{14}\)
\(\Rightarrow\frac{12}{14}=\frac{12}{14}\)
\(\Rightarrow\frac{6}{7}=\frac{12}{14}\)
b,\(\frac{2}{3}...\frac{3}{4}\)
\(\frac{2}{3}=\frac{2.4}{3.4}=\frac{8}{12}\)
\(\frac{3}{4}=\frac{3.3}{4.3}=\frac{9}{12}\)
\(\Rightarrow\frac{8}{12}< \frac{9}{12}\)
\(\Rightarrow\frac{2}{3}< \frac{3}{4}\)
\(\frac{6}{7}\)\(=\)\(\frac{12}{14}\)
\(\frac{2}{3}\)\(>\)\(\frac{3}{4}\)
\(\frac{12}{9}x\frac{3}{7}+\frac{8}{3}x\frac{10}{14}\)
\(=\frac{4}{3}x\frac{3}{7}+\frac{8}{3}x\frac{5}{7}\)
\(=\frac{4}{7}+\frac{40}{21}\)
\(=\frac{12}{21}+\frac{40}{21}\)
\(=\frac{52}{21}\)
Tham khảo nha !!!
2 tk m nhé
=1+1=2