Bài 1:tính giá trị biểu thức sau:
\(B=\left(1-\frac{1}{21}\right).\left(1-\frac{1}{28}\right).\left(1-\frac{1}{36}\right)...\left(1-\frac{1}{1326}\right)\)
Bài 2 tìm x biết
\(a,1\frac{1}{30}:\left(24\frac{1}{6}-24\frac{1}{5}\right)-\frac{1\frac{1}{2}-\frac{3}{4}}{4x-\frac{1}{2}}=\left(-1\frac{1}{15}\right):\left(8\frac{1}{5}-8\frac{1}{3}\right)\)
\(b,\left|3x-\frac{2}{5}\right|=\frac{1}{35}+\left|\frac{-3}{7}\right|\)
\(c,-3\frac{1}{2}-\left(2x+\frac{1}{2}\right):\left(-\frac{3}{7}\right)=0\)
\(d,\left(x-4\right).\left(x+2\right)\le0\)với x thuộc z
giúp mk với
tìm x\(\in\) Q,biết:
a,\(\frac{x}{2}\left(\frac{3x}{5}\right)-\frac{13}{5}=-\left(\frac{7}{5}+\frac{7}{10}x\right)\)
b,\(\frac{2x-3}{3}+\frac{-3}{2}=\frac{5-3x}{6}-\frac{1}{3}\)
c,\(\left(\frac{3}{2}-\frac{2}{-5}\right):x-\frac{1}{2}=\frac{3}{2}\)
d,\(\frac{13}{x-1}+\frac{5}{2x+2}-\frac{6}{3x-3}\)
e,\(\left(\frac{3}{2}-\frac{5}{11}-\frac{3}{13}\right)\left(2x-2\right)=\left(\frac{-3}{4}+\frac{5}{22}+\frac{3}{26}\right)\)
Ai bt câu nào làm câu đấy nhé ! Làm hết cũng đc nhé!
Tìm x, biết :
a, \(60\%x+0,4x+x:3=2\)
b, \(\left|2x-5\right|-7=\left(\frac{1}{49}-\frac{1}{3^2}\right)\left(\frac{1}{49}-\frac{1}{4^2}\right)...\left(\frac{1}{49}-\frac{1}{2015^2}\right)\)
c, \(\frac{x+1}{1}+\frac{2x+3}{3}+\frac{3x+5}{5}+...+\frac{20x+39}{39}=22+\frac{4}{3}+\frac{6}{5}+...+\frac{40}{39}\)
Giusp mình vs các bn ơi mình phải đi hk r
B1:Tìm x biết:
A)\(\frac{x-3}{2}=\frac{3x+1}{4}\) B) \(\frac{5x-3}{x+1}=\frac{5}{2}\)
C)\(\frac{5x-3x}{4}=\frac{2}{3}\) D)\(\frac{7}{4x+2}=\frac{4}{5}\)
E)\(\frac{4}{3x-2}=\frac{7}{2x+3}\) F)\(\left(x-1\right):3=\left(2x+5\right):2\)
G)\(5:\left(2x+3\right)=7:\left(x+1\right)\)
Bài 2:Tìm số nguyên x,y biết:
A) \(\left(x-3\right).\left(y+2\right)=7\)
B)\(\left(2x-1\right).\left(4x+4\right)=12\)
C)\(\left(5x-2\right)-\left(y-1\right)=-5\)
Các bạn ơi giúp mình nha mình thực sự cần gấp với cái bài 2 dấu (.) là dáu nhân nha
\(\left(3x-1\right).\left(\frac{-1}{2}x+5\right)=0\)
\(\frac{1}{4}+\frac{1}{3}:\left(2x-1\right)=-5\)
\(\left(2x+\frac{3}{5}\right)^{^2}-\frac{9}{25}=0\)
\(3\left(3x-\frac{1}{2}\right)+\frac{1}{9}=0\)
Tìm x,biết:
a) \(\frac{1}{2}.\left(2x+3\right)-\frac{1}{3}\left(5-3x\right)=\frac{3}{2}x+7\)
b) \(30.\left(2+x\right)-6.\left(x-5\right)-24.x=100\)
tìm số hữu tỷ x,biết
a, \(\frac{-3}{2}-2x+\frac{3}{4}=-2\)2
b,\(\left(\frac{-2}{3}x-\frac{3}{5}\right)\left(\frac{3}{-2}-\frac{10}{3}\right)=\frac{2}{5}\)
c,\(\frac{x}{2}-\left(\frac{3x}{5}-\frac{13}{5}\right)=-\left(\frac{7}{5}+\frac{7}{10}.x\right)\)
\(a,-\frac{2}{3}.\left(x-\frac{1}{4}\right)=\frac{1}{3}.\left(2x+1\right)\)
\(b,\frac{1}{5}.2^x+\frac{1}{3}.2^{x+1}=\frac{1}{5}.2^7+\frac{1}{3}:2^8\)
\(c,\left(x-y^2+z\right)^2+\left(y-2\right)^2+\left(z+3\right)^2=0\)
Tìm \(x\) biết:
a)\(\left|2x-5\right|-7=\left(\frac{1}{49}-\frac{1}{3^2}\right)\left(\frac{1}{49}-\frac{1}{4^2}\right).....\left(\frac{1}{49}-\frac{1}{2015^2}\right)\)
b)\(\frac{x+1}{1}+\frac{2x+3}{3}+\frac{3x+5}{5}+...+\frac{20x+39}{39}=22+\frac{4}{3}+\frac{6}{5}+...+\frac{40}{39}\)