A)\(75\%.x-\frac{3}{2}:\frac{5}{4}=3\frac{1}{2}+25\%\)

<=>\(\frac{3}{4}x-\frac{6}{5}=\frac{7}{2}+\frac{1}{4}\)

<=>\(\frac{3}{4}x=\frac{7}{2}+\frac{1}{4}+\frac{6}{5}\)

<=>\(\frac{3}{4}x=\frac{99}{20}\)

<=>\(x=\frac{33}{5}\)

B)\(\left(x-\frac{3}{4}\right).50\%-\frac{2}{7}=1+\frac{3}{4}\)

<=>\(\left(x-\frac{3}{4}\right)\cdot\frac{1}{2}=\frac{7}{4}\)

<=>\(\frac{1}{2}x-\frac{3}{8}=\frac{7}{4}\)

<=>\(\frac{1}{2}x=\frac{17}{8}\)

<=>\(x=\frac{17}{4}\)

C)\(\left(\frac{5}{6}-2\frac{1}{2}\right):x=\frac{2}{5}-\frac{1}{3}\)

<=>\(-\frac{5}{3}:x=\frac{1}{15}\)

<=>\(x=-\frac{25}{3}\)

D)\(\left(\frac{1}{4}-x\right)-\frac{1}{2}=2\frac{1}{2}+1\)

<=>\(\frac{1}{4}-x-\frac{1}{2}=\frac{7}{2}\)

<=>\(-\frac{1}{4}-x=\frac{7}{2}\)

<=>\(x=-\frac{15}{4}\)

\(\frac{5}{7}\times\frac{1}{3}-\frac{5}{7}\times\frac{1}{4}-\frac{5}{7}\times\frac{1}{2}\)

\(=\frac{5}{7}\times\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{2}\right)\)

\(=\frac{5}{7}\times\left(\frac{4}{12}-\frac{3}{12}-\frac{6}{12}\right)\)

\(=\frac{5}{7}\times\left(\frac{4-3-6}{12}\right)\)

\(=\frac{5}{7}\times\frac{-5}{12}\)

\(=\frac{5\times\left(-5\right)}{7\times12}\)

\(=\frac{-25}{84}\)

\(\frac{5}{7}.\frac{1}{3}-\frac{5}{7}.\frac{1}{4}-\frac{5}{7}.\frac{1}{2}\)

= \(\frac{5}{7}.\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{2}\right).1\)

\(=\frac{5}{7}.\frac{-5}{12}\)

\(=-\frac{25}{84}\)

\(75\%-1\frac{1}{2}+0,5:\frac{5}{12}-\left(\frac{-1}{2}\right)^2\)

= \(\frac{3}{4}-\frac{3}{2}+\frac{1}{2}:\frac{5}{12}-\frac{1}{4}\)

\(\frac{3}{4}-\frac{3}{2}+\frac{1}{2}.\frac{5}{12}-\frac{1}{4}\)

\(\frac{3}{4}-\frac{3}{2}+\frac{5}{24}-\frac{1}{4}\)

\(\frac{18}{24}-\frac{36}{24}+\frac{5}{24}-\frac{6}{24}\)

-19/24

i don't know i mới học lớp 5

bn eie mik lớp 6 nha bn

CACS BN GIÚP MIK TRẢ LỜI TRONG TỐI NAY ĐC K

\(a,\frac{-7}{25}.\frac{11}{13}+\frac{-7}{25}.\frac{2}{13}-\frac{18}{25}\)

\(=\frac{-7}{25}.\left(\frac{11}{13}+\frac{2}{13}\right)-\frac{18}{25}=\frac{-7}{25}-\frac{18}{25}=-1\)

\(b,\frac{5}{7}.\frac{1}{3}-\frac{5}{7}.\frac{1}{4}-\frac{5}{7}.\frac{1}{12}=\frac{5}{7}.\left(\frac{1}{3}-\frac{1}{4}-\frac{1}{12}\right)=\frac{5}{7}.\left(\frac{4}{12}-\frac{3}{12}-\frac{1}{12}\right)\)

\(=\frac{5}{7}.0=0\)

c)\(5\frac{2}{5}.4\frac{2}{7}+5\frac{5}{7}.5\frac{2}{5}=\frac{27}{5}.\frac{30}{7}+\frac{40}{7}.\frac{27}{5}=\frac{27}{5}.\left(\frac{30}{7}+\frac{40}{7}\right)\)

\(=\frac{27}{5}.10=27.2=54\)

\(d,75\%-1\frac{1}{2}+0,5:\frac{5}{12}-\left(\frac{-1}{2}\right)^2=\frac{3}{4}-\frac{3}{2}+\frac{1}{2}.\frac{12}{5}-\frac{1}{4}\)

\(=\left(\frac{3}{4}-\frac{1}{4}\right)-\frac{3}{2}+\frac{6}{5}=\frac{1}{2}-\frac{3}{2}+\frac{6}{5}=-1+\frac{6}{5}=\frac{-5}{5}+\frac{6}{5}=\frac{1}{5}\)

cho mk hỏi, bn có thể lm thêm c d dc ko

mai bn đăng lại nhé mk lm cho h đi ngủ

1. A = 75(4²⁰⁰⁴ + 4²⁰⁰³ +...+ 4² + 4 + 1) + 25

    A = 25 . [3 . (4²⁰⁰⁴ + 4²⁰⁰³ +...+ 4² + 4 + 1) + 1]

    A = 25 . (3 . 4²⁰⁰⁴ + 3 . 4²⁰⁰³ +...+ 3 . 4² + 3 . 4 + 3 + 1)

    A = 25 . (3 . 4²⁰⁰⁴ + 3 . 4²⁰⁰³ +...+ 3 . 4² + 3 . 4 + 4)

    A = 25 . 4 . (3 . 4²⁰⁰³ + 3 . 4²⁰⁰² +...+ 3 . 4 + 3 + 1)

    A =100 . (3 . 4²⁰⁰³ + 3 . 4²⁰⁰² +...+ 3 . 4 + 3 + 1) \(⋮\) 100

3a) |x| = 1/2 

=> x = 1/2 hoặc x = -1/2

với x = 1/2:

A = \(3.\left(\frac{1}{2}\right)^2-2.\frac{1}{2}+1\)

\(A=\frac{3}{4}-1+1=\frac{3}{4}\)

với x = -1/2

A = \(3.\left(-\frac{1}{2}\right)^2-2\left(-\frac{1}{2}\right)+1\)

\(A=\frac{3}{4}+1+1=\frac{3}{4}+2=\frac{11}{4}\)

2.

A=\(\frac{\left(1+2+3+.....+99+100\right)\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{7}-\frac{1}{9}\right)\left(63.1,2-21.3,6\right)}{1-2+3-4+......+99-100}\)\

A=0