Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Câu a:
2.(x + 2/5) + 1 1 /4 = 11/20
2x + 4/5 + 5/4 = 11/20
2x = 11/20 - 5/4 - 4/5
2x = 11/20 - 25/20 - 16/20
2x = -30/20
2x = -3/2
x = -3/2 : 2
x = - 3/4
Vậy x = - 3/4
Câu b:
x - 1 1/8 - 2/3x - 5/6x = 75%
(x - 2/3x - 5/6x) = 75% + 1 1/8
x (1 - 2/3 - 5/6) = 3/4 + 9/8
x (6/6 - 4/6 - 5/6) = 6/8 + 9/8
x.(-1/2) = 15/8
x = 15/8 : (-1/2)
x = 15/8 x (-2)
= -15/4
a) \(2.\left(x+\frac{2}{5}\right)+1\frac{1}{4}=\frac{11}{20}\)
\(2.\left(x+\frac{2}{5}\right)+\frac{5}{4}=\frac{11}{20}\)
\(2.\left(x+\frac{2}{5}\right)=\frac{-7}{10}\)
\(x+\frac{2}{5}=\frac{-7}{20}\)
\(x=\frac{-13}{20}\)
Vậy \(x=\frac{-13}{20}\)
b)\(x-1\frac{1}{8}-\frac{2}{3}x-\frac{5}{6}x=75\%\)
\(\left(x-\frac{2}{3}x-\frac{5}{6}x\right)-\frac{9}{8}=\frac{3}{4}\)
\(\frac{-1}{2}x-\frac{9}{8}=\frac{3}{4}\)
\(\frac{-1}{2}x=\frac{15}{8}\)
\(x=\frac{-15}{4}\)
Vậy \(x=\frac{-15}{4}\)
Câu a:
1 1/3 + 2/3x = 5 1/3
2/3x = 5 1/3 - 1 1/3
2/3x = 4
x = 4 : 2/3
x = 4 x 3/2
x = 6
Vậy x = 6
a) \(\frac{3}{5}:\left(-\frac{1}{15}-\frac{1}{6}\right)+\frac{3}{5}:\left(-\frac{1}{3}-1\frac{1}{15}\right)\)
\(=\frac{3}{5}:\left(-\frac{1}{15}-\frac{1}{6}-\frac{2}{6}-1+\frac{1}{15}\right)\)
\(=\frac{3}{5}:\left(-\frac{1}{2}-1\right)\)
\(=\frac{3}{5}:\left(-\frac{3}{2}\right)\)
\(=-\frac{2}{5}\)
b) \(\left(-\frac{3}{4}+\frac{5}{13}\right):\frac{2}{7}-\left(2\frac{1}{4}+\frac{8}{13}\right):\frac{2}{7}\)
\(=\left(-\frac{3}{4}+\frac{5}{13}-2+\frac{1}{4}+\frac{8}{13}\right):\frac{2}{7}\)
\(=\left(-\frac{1}{2}+1-2\right):\frac{2}{7}\)
\(=\left(-\frac{1}{2}-1\right):\frac{2}{7}\)
\(=-\frac{3}{2}:\frac{2}{7}\)
\(=-\frac{21}{4}\)
Câu a:
x - 1: 4/3 + 9/16 = - 5^2/4^2
x - 1 x 3/4 + 9/16 = - 25/16
x - 3/4 + 9/16 = - 25/16
x - 3/4 = -25/16 - 9/16
x - 3/4 = -17/8
x = - 17/8 + 3/4
x = -11/8
Vậy x = -11/8
Câu b:
5/2x + 2 - 3 1/2 = 1/6
5/2x + 2 - 7/2 = 1/6
5/2x = 1/6 + 7/2 - 2
5/2x = 1/6 + 21/6 - 12/6
5/2x = 5/3
x = 5/3 : 5/2
x = 2/3
1/2+1/4+1/6+1/8+1/16):x=3/1*2+3/2*3+3/3*4+...+3/15*16
\(\frac{53}{48}:x=3(\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{15.16})\)
\(\frac{53}{48}:x=3(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{15}-\frac{1}{16})\)
\(\frac{53}{48}:x=3(1-\frac{1}{16})\)
\(\frac{53}{48}:x=\frac{45}{16}\)
\(x=\frac{53}{48}:\frac{45}{16}\)
\(x=\frac{53}{135}\)
Chúc bạn học tốt
1) \(-1,6:\left(1+\frac{8}{12}\right)\)
\(=-1,6:\left(1+\frac{2}{3}\right)\)
\(=-1,6:1-1,6:\frac{2}{3}\)
\(=-1,6+\frac{-1,6.3}{2}\)
\(=-1,6-2,4\)
\(=4\)
2) \(\frac{3}{8}-\frac{4}{5}-\frac{-17}{40}\)
\(=\frac{15-32+17}{40}\)
=0
3) \(\frac{3}{4}-\frac{16}{32}+\frac{4}{-3}\)
\(=\frac{3}{4}-\frac{2}{4}+\frac{-4}{3}\)
\(=\frac{9-6-16}{12}\)
\(=\frac{-13}{12}\)
4) \(\frac{-4}{7}+\frac{2}{3}.\frac{-9}{14}\)
\(=\frac{-4}{7}+\frac{-3}{7}=-1\)
5) \(2\frac{3}{4}-\left(\frac{1}{7}+1\frac{3}{4}\right)\)
\(=\frac{11}{4}-\left(\frac{1}{7}+\frac{7}{4}\right)\)
\(=\frac{11}{4}-\frac{4+49}{28}\)
\(=\frac{11}{4}-\frac{53}{28}\)
\(=\frac{77-53}{28}=\frac{24}{28}=\frac{6}{7}\)
6) \(8\frac{2}{7}-\left(3\frac{4}{9}+4\frac{2}{7}\right)\)
\(=\frac{58}{7}-\left(\frac{31}{9}+\frac{30}{7}\right)=\frac{522-217+270}{63}\)
\(=\frac{575}{63}\)