Tính \(C=\frac{3}{24}+\frac{5}{126}+\frac{7}{295}+\frac{8}{169}\)
Tính A=\(\frac{\frac{3}{5}+\frac{3}{7}+\frac{3}{13}+\frac{3}{295}}{\frac{4}{5}+\frac{4}{7}+\frac{4}{13}+\frac{4}{295}}\)
A=\(\frac{3}{5}\): \(\frac{4}{5}\) + \(\frac{3}{7}\):\(\frac{4}{7}\)+ \(\frac{3}{13}\): \(\frac{4}{13}\)+\(\frac{3}{295}\): \(\frac{4}{295}\)
A= \(\frac{3}{4}\)+ 3/4 + 3/4 + 3/4
A=3/4 . 4 = 3
Ta có: \(\frac{3}{5}+\frac{3}{7}+\frac{3}{13}+\frac{3}{295}=3.\left(1+\frac{1}{5}+\frac{1}{7}+\frac{1}{13}+\frac{1}{295}\right)\)
\(\frac{4}{5}+\frac{4}{7}+\frac{4}{13}+\frac{4}{295}=4.\left(1+\frac{1}{5}+\frac{1}{7}+\frac{1}{13}+\frac{1}{295}\right)\)
\(\Rightarrow\frac{\frac{3}{5}+\frac{3}{7}+\frac{3}{13}+\frac{3}{295}}{\frac{4}{5}+\frac{4}{7}+\frac{4}{13}+\frac{4}{295}}=\frac{3.\left(1+\frac{1}{5}+\frac{1}{7}+\frac{1}{13}+\frac{1}{295}\right)}{4.\left(1+\frac{1}{5}+\frac{1}{7}+\frac{1}{13}+\frac{1}{295}\right)}=\frac{3}{4}\)
\(A=\frac{\frac{3}{5}+\frac{3}{7}+\frac{3}{13}+\frac{3}{295}}{\frac{4}{5}+\frac{4}{7}+\frac{4}{13}+\frac{4}{295}}=\frac{3\left(\frac{1}{5}+\frac{1}{7}+\frac{1}{13}+\frac{1}{295}\right)}{4\left(\frac{1}{5}+\frac{1}{7}+\frac{1}{13}+\frac{1}{295}\right)}=\frac{3}{4}\)
Tính nhanh
A=\(\frac{7.9+14.27+21.36}{21.27+42.81+63.108}\)
B=\(\frac{\frac{1}{3}-0,25+\frac{1}{5}}{1\frac{1}{6}-0,875+0,7}+\frac{5+\frac{5}{13}-\frac{5}{169}+\frac{5}{91}}{7+\frac{8}{13}-\frac{7}{169}}\)
\(A=\frac{7\times9+14\times27+21\times36}{21\times27+42\times81+63\times108}=\frac{7\times9+7\times2\times9\times3+7\times3\times9\times4}{21\times27+21\times2\times27\times3+21\times3\times27\times4}=\frac{7\times9\times\left(1+2\times3+3\times4\right)}{21\times27\times\left(1+2\times3\times3\times4\right)}=\frac{7\times3\times3}{7\times3\times3\times9}=\frac{1}{9}\)
Tính giá trị biểu thức
a,\(A=\frac{24\cdot47-23}{24+47-23}\cdot\frac{3+\frac{3}{7}-\frac{3}{11}+\frac{3}{1001}-\frac{3}{13}}{\frac{9}{1001}-\frac{9}{13}+\frac{9}{7}-\frac{9}{11}+9}\)
b,\(M=\frac{1+2+2^2+2^3+...+2^{2012}}{2^{2014}-2}\)
c,\(A=81\cdot\left[\frac{12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}}{4-\frac{4}{7}-\frac{4}{289}-\frac{4}{85}}:\frac{5+\frac{5}{13}+\frac{5}{169}+\frac{5}{91}}{6+\frac{6}{13}+\frac{6}{169}+\frac{6}{91}}\right]:\frac{158158158}{711711711}\)
d,\(A=\frac{5\cdot\left(2^2.3^2\right)^9\cdot\left(2^2\right)^6-2\cdot\left(2^2\cdot3\right)^{14}\cdot3^4}{5\cdot2^{28}\cdot3^{18}-7\cdot2^{29}\cdot3^{18}}\)
tính bằng cách hợp lý
\(\frac{3}{54}+\frac{5}{126}+\frac{7}{294}\) chia \(\frac{5}{24}+\frac{5}{104}+\frac{5}{234}\)
Tính giá trị của biểu thức, tính nhanh nếu có thể
\(\frac{\frac{3}{54}+\frac{5}{126}+\frac{7}{194}}{\frac{5}{24}+\frac{5}{104}+\frac{5}{234}}\)
Các bạn giúp mk nhé, mk xin cảm ơn
Tính:
a) \(\frac{2}{7}:\frac{13}{24}+\frac{2}{7}:\frac{5}{24}\)
b)\(\frac{15}{24}-\frac{3}{8}-\frac{1}{6}\)
c)\(\frac{7}{13}.\frac{5}{14}.\frac{39}{15}\)
a)<=>2/7:(13/24+5/24) b)<=>15/24-9/24-4/24 c)=7.5.39/13.14.15
<=>2/7:3/4 <=>2/24=1/12 =3/2.3
<=>2/7x4/3 =1/2
<=>8/21
a. \(\frac{2}{7}:\frac{13}{24}+\frac{2}{7}:\frac{5}{24}\)
= \(\frac{2}{7}:\left(\frac{13}{24}+\frac{5}{24}\right)\)
= \(\frac{2}{7}:\frac{3}{4}\)
= \(\frac{8}{21}\)
b. \(\frac{15}{24}-\frac{3}{8}-\frac{1}{6}\)
= \(\frac{15}{24}-\frac{9}{24}-\frac{4}{24}\)
= \(\frac{2}{24}=\frac{1}{12}\)
c. \(\frac{7}{13}.\frac{5}{14}.\frac{39}{15}\)
= \(\frac{7.5.3.13}{13.2.7.3.5}\)
= \(\frac{1}{2}\)
\(a,\frac{2}{7}:\frac{13}{24}+\frac{2}{7}:\frac{5}{24}\)
\(=\frac{2}{7}\cdot\frac{24}{13}+\frac{2}{7}\cdot\frac{24}{5}\)
\(=\frac{2}{7}\left(\frac{24}{13}+\frac{24}{5}\right)\)
\(=\frac{2}{7}\cdot\frac{432}{65}\)
\(=\frac{864}{455}\)
\(b,\frac{15}{24}-\frac{3}{8}-\frac{1}{6}\)
\(=\frac{1}{4}-\frac{1}{6}\)
\(=\frac{1}{12}\)
\(c,\frac{7}{13}\cdot\frac{5}{24}\cdot\frac{39}{15}\)
\(=\frac{7\cdot5\cdot39}{13\cdot24\cdot15}\)
\(=\frac{7}{24}\)
Thực hiện phép tính:
a)\(\frac{26.108-26.12}{32-28+24-20+16-12+8-4}\)
b)\(12-\frac{12}{7}-\frac{12}{289}-\frac{12}{85}\)
c) \(3+\frac{3}{13}+\frac{3}{169}+\frac{3}{91}\)
Các bn giúp mk nhé mk đg cần gấp lắm nhé
A,
26 x 108 - 26 x 12
32-28 + 24 - 20 + 16- 12 + 8 -4
26x (108 - 12 )
4 + 4 + 4 +4
26 x 96
4x4
=156
bài 1:thực hiện phép tính :
a)\(\frac{3}{7}+\frac{5}{13}+\frac{4}{13}\)
b)\(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
c)\(\frac{2}{5}.\frac{1}{3}-\frac{2}{15}:\frac{1}{5}+\frac{3}{5}.\frac{1}{3}\)
d)\(\left(4-\frac{5}{12}\right):2+\frac{5}{24}\)
e)\(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-1}{19}\)
f)\(\frac{9}{27}+\frac{8}{24}+\frac{18}{27}-\frac{-16}{24}+\frac{2}{3}\)
g)\(\frac{-5}{21}+\frac{-2}{21}+\frac{8}{24}\)
h)\(\frac{-5}{9}+\frac{8}{15}+\frac{-2}{11}+\frac{4}{-9}+\frac{7}{15}\)
i)\(\frac{7}{25}.\frac{39}{-14}.\frac{50}{78}\)
m.n làm nhanh cho mình nhé, chiều mình phải nộp rồi! cảm ơn m.n!
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 =\(\frac{1\times2+2\times4+3\times6+4\times8+5\times10}{3\times4+6\times8+9\times12+12\times16+15\times20}\)