Bài 1.
A=( 45 x 46 + 47 x48 ) x ( 51 x 52 - 49 x 48 ) x ( 45 x 128 - 90 x 64 ) x (1995 x 1996 + 1997 x 1998 )
Bài 2.
\(\frac{7}{13}\)x\(\frac{5}{6}\)x\(\frac{5}{13}\)
Bài 3.
\(\frac{75}{100}\)+\(\frac{18}{21}\)+\(\frac{19}{32}\)+\(\frac{1}{4}\)+\(\frac{3}{21}\)+\(\frac{13}{32}\)
Bài 4.Tính giá trị biểu thức:
a.0,1 + 0,2 + 0,3 + ... + 0,9 + 0,10 + 0,11 + ... + 0,19
b.(1999 x 1998 + 1998 x 1997) x (1 +\(\frac{1}{2}\):1\(\frac{1}{2}\)- 1\(\frac{1}{3}\))
GIÚP MÌK NHA MÌK CẦN GẤP
\(\frac{1}{4}+\frac{1}{3}\left(2x-1\right)=-5\)
\(\frac{2}{3}x-\frac{1}{2}=\frac{1}{10}\)
\(\left(x.6\frac{2}{7}+\frac{3}{7}\right).2\frac{1}{5}-\frac{3}{7}=-2\)
\(5\frac{4}{7}:x=13\)
\(\left(2\frac{4}{5}x-50\right):\frac{2}{3}=51\)
làm hộ mik nhanh vs ... mik chỉ còn 50p nữa là nộp pài r
\(-5\left(x+\frac{1}{5}\right)-\frac{1}{2}\left(x-\frac{2}{3}\right)=\frac{3}{2}x-\frac{5}{6}\)
tìm x biết :
\(a,\frac{1}{2}-\frac{2}{3}x=\frac{7}{12}\) b,/x+\(\frac{1}{2}\)/=\(\frac{3}{4}\)
Tìm x:
a, \(\frac{-1}{5}\) ≤ \(\frac{x}{8}\) ≤ \(\frac{1}{4}\)
b, \(\frac{x+46}{20}\) = \(x\frac{2}{5}\)
bài 1:
a, (1-\(\frac{3}{6}\)2)+/\(\frac{-7}{23}\)/+(-\(\frac{4}{25}\))
b, \(\sqrt{25}\)-\(\sqrt{100}\)+\(\sqrt{36}\)
c,(\(\frac{-31}{37}\))5.(\(\frac{37}{62}\))5
bài 2:
a,(x-\(\frac{3}{5}\))2=4
b,2x+2x+3=144
xg trc tick cho
Tìm x biết:
|\(3\frac{2}{9}+x\)| = \(\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}+\frac{1}{72}\)
a) \(\frac{2}{5}+\left(-\frac{4}{3}\right)+\left(-\frac{1}{2}\right)\)
b) \(\frac{5}{8}-\left(-\frac{2}{5}-\frac{3}{10}\right)\)
c) \(\frac{1}{3}-\left[\left(-\frac{5}{4}\right)-\left(\frac{1}{4}+\frac{3}{8}\right)\right]\)
d) \(\frac{2}{3}-4.\left(\frac{1}{2}+\frac{3}{4}\right)\)
e) \(\left(-\frac{1}{3}+\frac{5}{6}\right).11-7\)
f) \(\left(-\frac{5}{9}\right).\frac{3}{11}+\left(-\frac{13}{18}\right).\frac{3}{11}\)
a.\(\frac{34}{13}-\frac{19}{28}-\frac{3}{31}\)
b.\(\frac{7}{3}-\frac{11}{5}-\frac{4}{5}\)
c.\(\frac{18}{13}+\frac{55}{46}-\frac{5}{13}\)
Bài Tính Nhanh
bài 2:tính tổng đặc biệt:
\(E=\frac{1}{3}+\frac{1}{3^2}+\frac{1}{3^3}+...+\frac{1}{3^8}\)
Bài 3:chứng minh:
a,\(A=1+\frac{1}{2}+\frac{1}{3}+....+\frac{1}{99}\)chứng minh rằng \(A⋮100\)
b,\(A=\frac{1}{11}+\frac{1}{12}+\frac{1}{13}+...+\frac{1}{70}\)chứng minh rằng \(A>\frac{4}{3}\)
hlep me!!!!