Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
các phân số này bằng nhau là đương nhiên cái này là thi toán cấp huyện lớp 4
Ta có
a/ 1/3x - 3/4x = 5/12 1/4x + 3/4 +x =7/8
x(1/3-3/4)=5/12 2x=7/8
-5/12x=5/12 x=7/8 : 2 =7/16
x=5/12 : -5/12
x=-1
a) \(\frac{2}{3}x-\frac{1}{2}x=\frac{5}{12}\)
\(x\left(\frac{2}{3}-\frac{1}{2}\right)=\frac{5}{12}\)
\(x\left(\frac{4}{6}-\frac{3}{6}\right)=\frac{5}{12}\)
\(\frac{1}{6}x=\frac{5}{12}\)
\(x=\frac{5}{12}:\frac{1}{6}=\frac{5}{2}\)
b) \(25\%x+\frac{3}{4}x+x=\frac{7}{8}\)
\(x\left(25\%+\frac{3}{4}+1\right)=\frac{7}{8}\)
\(x\left(\frac{1}{4}+\frac{3}{4}+1\right)=\frac{7}{8}\)
\(x\left(1+1\right)=\frac{7}{8}\)
\(2x=\frac{7}{8}\)
\(x=\frac{7}{8}:2=\frac{7}{16}\)
\(\frac{7}{13}.\frac{5}{9}+\frac{7}{19}.\frac{8}{13}-3.\frac{7}{19}=\)\(\frac{-1288}{2223}\)
Bài 1:
\(\frac{3}{5}+\frac{4}{15}=\frac{9}{15}+\frac{4}{15}=\frac{13}{15}\)
\(\frac{5}{6}:\frac{-7}{12}=\frac{5}{6}.\frac{-12}{7}=\frac{-60}{42}=\frac{-10}{7}\)
\(\frac{-21}{24}:\frac{-14}{8}=\frac{-21}{24}.\frac{-8}{14}=\frac{168}{336}=\frac{1}{2}\)
\(\frac{4}{5}:\frac{-8}{15}=\frac{4}{5}.\frac{-15}{8}=\frac{-60}{40}=\frac{-3}{2}\)
\(\frac{5}{12}-\frac{-7}{6}=\frac{5}{12}+\frac{7}{6}=\frac{5}{12}+\frac{14}{12}=\frac{19}{12}\)
\(\frac{-15}{16}.\frac{8}{25}=\frac{-120}{400}=\frac{-3}{10}\)
Bài 2 :
\(6\frac{4}{5}-\left(1\frac{2}{3}+3\frac{4}{5}\right)\)
\(=\frac{34}{5}-\left(\frac{5}{3}+\frac{19}{5}\right)\)
\(=\frac{34}{5}-\frac{5}{3}-\frac{19}{5}\)
\(=\left(\frac{34}{5}-\frac{19}{5}\right)-\frac{5}{3}\)
\(=3-\frac{5}{3}\)
\(=\frac{4}{3}\)
\(6\frac{5}{7}-\left(1\frac{2}{3}+2\frac{5}{7}\right)\)
\(=\frac{47}{7}-\left(\frac{5}{3}+\frac{19}{7}\right)\)
\(=\frac{47}{7}-\frac{5}{3}-\frac{19}{7}\)
\(=\left(\frac{47}{7}-\frac{19}{7}\right)-\frac{5}{3}\)
\(=4-\frac{5}{3}\)
\(=\frac{7}{3}\)
\(\frac{4}{19}.\frac{-3}{7}+\frac{-3}{7}.\frac{15}{19}+\frac{5}{7}\)
\(=\left(\frac{4}{19}+\frac{15}{19}\right).\frac{-3}{7}+\frac{5}{7}\)
\(=1.\frac{-3}{7}+\frac{5}{7}\)
\(=\frac{-3}{7}+\frac{5}{7}\)
\(=\frac{2}{7}\)
\(\frac{5}{9}.\frac{7}{13}+\frac{5}{9}.\frac{9}{13}-\frac{5}{9}.\frac{3}{13}\)
\(=\frac{5}{9}.\left(\frac{7}{13}+\frac{9}{13}-\frac{3}{13}\right)\)
\(=\frac{5}{9}.1\)
\(=\frac{5}{9}\)
d. 37/53 x 535353/373737 x 23/48 x 242424/232323
= 1 x 1/2
= 1/2
37/53.23/48.535353/373737.242424/232323
=37/53.23/48.53/37.24/23
=37.23.53.24/53.48.37.23
=24/48
=1/2