\(a,\frac{3}{4}-x=1\) \(b,x+4=\frac{1}{5}\) \(c,x-\frac{1}{5}=2\)

\(d,x+\frac{5}{3}=\frac{1}{81}\) \(e,x-\frac{10}{3}=\frac{7}{15}.\frac{3}{5}\) \(g,x+\frac{3}{22}=\frac{27}{121}.\frac{11}{9}\)

\(h,1-x=\frac{49}{65}.\frac{5}{7}\) \(i,\frac{8}{23}.\frac{46}{24}-x=\frac{1}{3}\) \(k,\frac{62}{7}.x=\frac{29}{9}:\frac{3}{56}\)

bài 1 : tìm x biết

a, \(\frac{2}{3}\times\left(x-\frac{5}{6}\right)+\frac{1}{4}=\frac{22}{9}\)

b, \(\frac{2}{3}:\frac{x}{5}=\frac{10}{21}\)

c, \(\frac{7}{3}:\frac{x}{5}=\frac{14}{15}\)

d, \(1-\left(5\frac{4}{9}\times x-7\frac{7}{18}\right):15\frac{3}{4}=0\)

bài 2 : tính gtri bt

a,\(\frac{8}{7}+\frac{1}{5}\times\frac{10}{9}\)

b, \(\frac{3}{2}+\left(\frac{9}{2}+\frac{2}{9}\right)\times\left(\frac{4}{3}-\frac{5}{4}\right)\)

!_ove

bài 1 tìm x,y,z 

a,\(\frac{x}{10}\)=\(\frac{y}{15}\),x=\(\frac{7}{2}\)và x+2y-3z=20

b,2x=3y,49=57 và 4x-3y+5z=7

c,\(\frac{2x}{3}\)=\(\frac{3y}{4}\)=\(\frac{47}{5}\)và x+y+z=49

2 tìm x trong các tỉ lệ thức sau

a, \(\frac{x-3}{x+5}=\frac{5}{7}\)

 b,\(\frac{7}{x-1}\)\(=\frac{x+1}{9}\)

c \(\frac{x+4}{20}=\frac{5}{x+4}\)

d,\(\frac{x-1}{x+2}=\frac{x-2}{x+3}\)

bài 3: tìm các số x,y,z

a,\(\frac{x}{y}=\frac{7}{10}=\frac{z}{9}\)

b,\(\frac{x}{y}=\frac{9}{7};\frac{y}{z}=\frac{7}{3}\) và x-y+z=-15

c,\(\frac{x}{y}=\frac{7}{20};\frac{y}{z}=\frac{5}{8}\)và 2x+5y-2z=100

bài 4 tìm các số x,y,z

a,5x=8y=20z và x-y-z=3 

b ,\(\frac{6}{11}x=\frac{9}{2}y=\frac{18}{5}z\)và -x+y+z=-120

bài 5 tìm x,y,z biết

và xyz=20

bài 6 tìm x,y,z biết

\(\frac{x}{5}=\frac{y}{7}=\frac{z}{3}\)và x²  + y² -z² =585

Bài 1: tìm x:

a)\(\frac{2}{3}\).x-\(\frac{3}{2}\).x=\(\frac{5}{12}\)

b) \(\frac{7}{9}\):(2+\(\frac{3}{4}\).x)+\(\frac{5}{9}\)=\(\frac{23}{27}\)

c)\(\frac{2}{5}\)+\(\frac{3}{5}\).(3x-3,7)= -\(\frac{53}{10}\)

bài 2 tìm x

a,\(\frac{-2}{3}.x+\frac{1}{5}=\frac{3}{10}\)

b,\(\left|x\right|-\frac{3}{4}=\frac{5}{3}\)

c,\(\frac{2}{3}.x-\frac{1}{2}=\frac{1}{10}\)

d,\(\frac{3}{5}+\frac{4}{9}:x=\frac{2}{3}\)

e,\(\left|x+75\%\right|=2\frac{1}{5}\)

i,\(\left(x+\frac{1}{2}\right).\left(\frac{2}{3}-2.x\right)=0\)

k,\(\frac{4}{7}.x-\frac{2}{3}=\frac{1}{5}\)

l,\(\frac{2}{3}.x-\frac{3}{2}.x=\frac{5}{12}\)

m,\(\left|2.x-\frac{1}{3}\right|+\frac{5}{6}=1\)

n,\(\frac{1}{3}-\frac{7}{8}.x=\frac{1}{3}\)

11,\(\frac{x+2}{5}=\frac{7}{12}-1\frac{1}{4}\)

12,\(\left(2\frac{4}{5}.x-50\right):\frac{2}{3}=51\)

13,\(\frac{2}{5}+\frac{3}{5}.\left(3.x-3,7\right)=-\frac{53}{10}\)

14,\(\frac{7}{9}:\left(2+\frac{3}{4}.x\right)+\frac{5}{9}=\frac{23}{27}\)

Tính a) (4 \(\frac{5}{37}\)- 3\(\frac{4}{5}\)+8\(\frac{15}{29}\)) - (3\(\frac{5}{37}\)- 6\(\frac{14}{29}\)

b) 60 \(\frac{7}{13}\)x (8\(\frac{7}{10}\)) +50\(\frac{8}{13}\)x (-8 \(\frac{7}{10}\)) - 11 \(\frac{2}{13}\)x (-8 \(\frac{7}{10}\)

c) (2 \(\frac{5}{6}\)+ 1\(\frac{4}{9}\)) : ( 10 \(\frac{1}{2}\)- 9 \(\frac{1}{2}\)

d) 1 \(\frac{5}{18}\)- \(\frac{5}{18}\)x (\(\frac{1}{15}\)+1\(\frac{1}{12}\))

e)\(\frac{-1}{7}\)x (9 \(\frac{1}{2}\) - 8,75) :\(\frac{2}{7}\) +0,625 :1 \(\frac{2}{3}\)

BÀI 1 THỰC HIỆN PHÉP TÍNH :

A, \(\frac{25}{4}\)+\(\frac{-5}{4}\)          B,\(\frac{-5}{9}\)+\(\frac{-2}{7}\)         C,\(\frac{1}{4}\)+\(\frac{9}{11}\)+\(\frac{7}{4}\)+\(\frac{-2}{11}\)         D,\(\frac{-5}{19}\)*\(\frac{8}{19}\)+\(\frac{-14}{19}\)*\(\frac{11}{19}\)

BÀI 2: TÌM X BIẾT

A, X+\(\frac{5}{9}\)=\(\frac{-8}{9}\)       B,\(\frac{-1}{8}\)-X=\(\frac{9}{20}\)         C,( X + 5)\(^3\)-12=15                 D,/X-3/-\(\frac{4}{15}\)=\(\frac{26}{15}\)