tính nhanh
e) \(\frac{0,1997+2,5\cdot12,5\cdot0,4\cdot0,08+0,8003}{1,25\cdot2,5\cdot8\cdot4}\)
g)\(\frac{\left(10,6524+0,3476\right)\cdot125\cdot0,4+8}{4\cdot0,1\cdot8\cdot0,25\cdot125}\)
tinh nhanh
\(\frac{25\cdot4-0,5\cdot40\cdot5\cdot0,2\cdot20\cdot0,25}{1+2+8+............+129+156}\)
\(\frac{0,5\cdot40-0,5\cdot20\cdot8\cdot0,1\cdot0,25\cdot10}{128:8\cdot16\cdot\left(4+52:4\right)}\)
a)\(\frac{25.4-0,5\cdot40\cdot0,2\cdot20\cdot0,25}{1+2+8+...+129+156}\)
\(=\frac{100-100}{1+2+8+...+156}\)
\(=\frac{0}{1+2+8+...+156}\)
\(=0\)
b)\(\frac{0,5\cdot40-0,5\cdot20\cdot8\cdot0,1\cdot0,25\cdot10}{128:8.16.4\left(4+52:4\right)}=\frac{20-20}{128:8.16.4.\left(4+52:4\right)}=\frac{0}{128:8.16.4.\left(4+52:4\right)}=0\)
tính\(\frac{9^{4^{ }}\cdot27^5\cdot3^6\cdot4^4}{3^8\cdot8^{14}\cdot24\cdot3\cdot8^2}\)
\(\frac{5\cdot415\cdot9^9-4\cdot3^{20}\cdot8^9}{5\cdot2^9\cdot2^{19}-7\cdot2^{19}.27^6}\)
\(\frac{8^5\cdot24^4\cdot72^2}{16^{12}\cdot125^2\cdot94^4}\)
Câu 1 : \(1,321338308x10^{-4}\)
Câu 2 : \(1316,572106\)
Câu 3 : \(1,641302619x10^{-13}\)
Ủng hộ nhé,tớ đang âm.
Rút gọn biểu thức sau :
a/ A = \(\frac{8\cdot4\cdot125\cdot25+96524+3476}{10\cdot125\cdot4\cdot25\cdot8}\)
b/ B = \(\frac{5+55+555+5555}{9+99+999+9999}\)
( dấu chấm là dấu nhân nha)
\(A=\frac{8\cdot4\cdot125\cdot25+96524+2476}{10\cdot125\cdot4\cdot25\cdot8}\)
\(A=\frac{1+96524+2476}{10}\)
\(A=\frac{99001}{10}\)
\(B=\frac{5+55+555+5555}{9+99+999+9999}\)
\(B=\frac{9}{5}\)
\(\frac{0,8\cdot0,04\cdot1,25\cdot25+0,6524+0.3476}{10\cdot125\cdot4\cdot25\cdot8}\)
làm giúp mik, mik vộiiii
\(\frac{0,8.0,04.1,25.25+0,6524+0,3476}{10.125.4.25.8}\)
\(=\frac{\left(0,8.1,25\right).\left(0,04.25\right)+\left(0,6524+0,3476\right)}{10.\left(125.8\right).\left(25.4\right)}\)
\(=\frac{1.1+1}{10.1000.100}\)
\(=\frac{1}{500000}\)
nếu mà ra phân số thì mình tính là \(\frac{2}{1000000}\)
nếu mà mình lấy 2:1000000=0,000002
chưa chắc là mình tính đúng đâu bạn nhớ tính lại nhé
chú bạn học giỏi nha
tính nhanh
\(\frac{0,8\cdot0,4\cdot1,25\cdot25+0,725+0,275}{1,25\cdot4\cdot8\cdot25}\) \(\frac{9,6\cdot0,2\cdot15,4\cdot2\cdot15,4:0,25}{30,8:0,5\cdot40:0,125\cdot5\cdot6}\)
=\(\frac{\left(0,8.1,25\right).\left(0,4.25\right)+1}{\left(4.25\right).\left(1,25.8\right)}\)=\(\frac{1.10}{100.10}=\frac{10}{1000}=\frac{1}{100}\)
\(B=\frac{2\cdot4+2\cdot4\cdot8+4\cdot8\cdot16+8\cdot16\cdot32}{3\cdot4+2\cdot6\cdot8+4\cdot12\cdot16+8\cdot24\cdot32}\)
\(B=\frac{2.4+2.4.8+4.8.16+8.16.32}{3.4+2.6.8+4.12.16+8.24.32}\)
\(B=\frac{2.4+2.4.8+4.2.4.16+2.4.16.32}{3.4+2.2.3.2.4+4.3.4.16+2.4.8.3.32}\)
\(B=\frac{2.4.\left(1+8+4.16+16.32\right)}{3.4.\left(1+2.2.2+4.16+2.8.32\right)}\)
\(B=\frac{2.4.\left(1+8+4.16+16.32\right)}{3.4.\left(1+8+4.16+16.32\right)}\)
\(B=\frac{2}{3}\)
Chúc bn học tốt !!!!
So sánh:
\(\frac{2\cdot4+2\cdot4\cdot8+4\cdot8\cdot16+8\cdot16\cdot32}{3\cdot4+2\cdot6\cdot8+4\cdot12\cdot16+8\cdot24\cdot32}\)với \(\frac{202}{304}\)
tìm x
\(\left(x+\frac{1}{2\cdot4}\right)+\left(x+\frac{1}{4\cdot6}\right)+\left(x+\frac{1}{6\cdot8}\right)+\left(x+\frac{1}{8\cdot10}\right)+\left(x+\frac{1}{10\cdot12}\right)=50\frac{5}{24}\)
\(\frac{2}{2\cdot4}+\frac{2}{4\cdot6}+\frac{2}{6\cdot8}+..............+\frac{2}{x\cdot\left(x+2\right)}=\frac{4}{9}\)
ĐKXĐ: \(x\ne0;x\ne-2\)
\(\frac{2}{2.4}+\frac{2}{4.6}+\frac{2}{6.8}+...+\frac{2}{x\left(x+2\right)}=\frac{4}{9}\)
\(\Leftrightarrow\)\(\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+...+\frac{1}{x}-\frac{1}{x+2}=\frac{4}{9}\)
\(\Leftrightarrow\)\(\frac{1}{2}-\frac{1}{x+2}=\frac{4}{9}\)
\(\Leftrightarrow\)\(\frac{1}{x+2}=\frac{1}{18}\)
\(\Rightarrow\)\(x+2=18\)
\(\Leftrightarrow\)\(x=16\) (t/m ĐKXĐ)
Vậy...
1/2(1-1/4+1/4-1/6+1/6-1/8+...+1/x-1/x+2)=4/9
1/2(1-1/x+2)=4/9
1- 1/x+2=4/9:1/2
1 - 1 /x+2=8/9
1/x+2=1-8/9
1/x+2=1/9
suy ra x+2=9
x=9-2
x=7
\(\frac{2}{2\cdot4}+\frac{2}{4\cdot6}+\frac{2}{6\cdot8}+................+\frac{2}{x\left(x+2\right)}=\frac{4}{9}\)
\(\Rightarrow\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+.....+\frac{1}{x}-\frac{1}{x+2}=\frac{4}{9}\)
\(\Rightarrow\frac{1}{2}-\frac{1}{x+2}=\frac{4}{9}\Rightarrow\frac{x+2-2}{2x+4}=\frac{4}{9}\Rightarrow9x=8x+16\)
\(\Rightarrow x=16\)