Tính\(\frac{^{6^3+3\times6^2+3^3}}{13}\)
Tính = cách nhanh nhất
\(\frac{6^3+3\times6^2+3^3}{-13}\)
= (2.3)^3+ 3. ( 2.3)^2 + 3^3 / -13
= 2^3 .3^3 + 3. 3^2 . 2^2 + 3^3 / -13
= 3^3. ( 2^3 + 2^2 + 1) /-13
= 27.13/-13
= -27
\(\frac{6^3+3\cdot6^2+3^3}{-13}=\frac{6^2\left(6+3\right)+3^2\cdot3}{-13}=\frac{36\cdot9+9\cdot3}{-13}=\frac{39\cdot9}{-13}=-3\cdot9=-27\)
Đáp số: A = | |
A = \(\dfrac{1}{3\times6}\) + \(\dfrac{1}{6\times9}\) + \(\dfrac{1}{9\times12}\)+...+\(\dfrac{1}{144\times147}\)
A = \(\dfrac{1}{3}\) \(\times\)( \(\dfrac{3}{3\times6}\) + \(\dfrac{3}{6\times9}\)+\(\dfrac{1}{9\times12}\)+...+\(\dfrac{3}{144\times147}\))
A = \(\dfrac{1}{3}\) \(\times\)(\(\dfrac{1}{3}-\dfrac{1}{6}+\dfrac{1}{6}-\dfrac{1}{9}+\dfrac{1}{9}-\dfrac{1}{12}+...+\dfrac{1}{144}-\dfrac{1}{147}\))
A = \(\dfrac{1}{3}\)\(\times\)(\(\dfrac{1}{3}\) - \(\dfrac{1}{147}\))
A = \(\dfrac{1}{3}\) \(\times\)\(\dfrac{16}{49}\)
A = \(\dfrac{16}{147}\)
Tính nhanh:\(\frac{1\times2\times3+2\times4\times6+3\times6\times9+4\times8\times12+5\times10\times15}{1\times3\times5+2\times6\times10+3\times9\times15+4\times12\times20+5\times15\times25}-\frac{1+2+3+2+4+6+3+6+9+4+8+12+5+10+15}{1+3+5+2+6+10+3+9+15+4+12+20+5+15+25}\)
\(\dfrac{6^3+3\times6^5+18^3}{-13\times6^3}\)
tính giá trị biểu thúc : \(\frac{1}{2}\times\frac{2\times6}{3\times6\times8}\times\frac{4\times6}{6\times2\times2}\times\frac{4\times5\times2}{2\times8\times10}\)
\(\frac{1.2.6.4.6.4.5.2}{2.3.6.8.6.2.2.2.8.10}=\frac{1}{96}\)
Gía trị của biểu thức là : \(\frac{1x2x3x2x2x2x2x3x2x2x2x5x2}{2x3x3x2x4x2x3x2x2x2x2x4x2x5x2}\)= \(\frac{1}{48}\)
Bài 4: Tính nhanh:
a, A =\(\left(\frac{84}{13}\right)^2+\left(\frac{35}{13}\right)^2\)
b, B = \(\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}\div\frac{3+\frac{3}{13}+\frac{3}{169}+\frac{3}{91}}{7+\frac{7}{13}+\frac{7}{169}+\frac{7}{91}}\)
c, C =\(\frac{1\times2+2\times4+3\times6+4\times8+5\times10}{3\times4+6\times8+9\times12+12\times16+15\times20}\)
Tính :\(\frac{5^2\times6^{11}\times6^2\times12^6\times15^2}{2\times6^{12}\times10^4-81^2\times960^3}\)
CẦN GẤP !! TRÌNH BÀY ĐẦY ĐỦ !!!
thực hiện phép tính (tính nhanh nếu có thể) :
a)\(1\frac{3}{19}+\frac{8}{21}-\frac{3}{19}+0.5+\frac{13}{21}\)
b)\(\left(-\frac{3}{4}+\frac{2}{7}\right):\frac{3}{7}+\left(\frac{5}{7}+\frac{-1}{4}\right):\frac{3}{7}\)
c)\(\left(\frac{1}{6}\right)^7\times6\)
d)\(\left(\frac{-1}{2}\right)^3+\frac{1}{2}:3\)
a) \(1\frac{3}{19}+\frac{8}{21}-\frac{3}{19}+0.5+\frac{13}{21}\)
\(=\left(1\frac{3}{19}-\frac{3}{19}\right)+\left(\frac{8}{21}+\frac{13}{21}\right)+0.5\)
\(=1+1+0.5=2.5\)
b) \(\left(-\frac{3}{4}+\frac{2}{7}\right):\frac{3}{7}+\left(\frac{5}{7}+\frac{-1}{4}\right):\frac{3}{7}\)
\(=\left(\frac{-3}{4}+\frac{2}{7}+\frac{5}{7}+\frac{-1}{4}\right):\frac{3}{7}\)
\(=0:\frac{3}{7}=0\)
tìm giá trị của các biểu thức sau
a. \(\frac{2^7\times9^3}{6^5\times8^2}\) b, \(\frac{6^3+3\times6^2+3^3}{-13}\)
\(\frac{2^7.3^6}{6^5.8^2}\)= \(\frac{2^7.3^6}{3^5.2^5.2^6}\)=\(\frac{2^7.3^6}{3^5.2^{11}}\)=\(\frac{3}{2^4}\)=\(\frac{3}{16}\)
đó là ý kiến của mình
\(a.\frac{2^7\times9^3}{6^5\times8^2}\)
\(=\frac{3}{16}\)
\(b.\frac{6^3+3\times6^2+3^3}{-13}\)
\(-\frac{333}{13}\)