Ôn tập toán 6
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Bài 1: Tính hợp lý:
a. 1152 - (374 + 1152) + (374 - 65)
b. dfrac{7}{12} + dfrac{5}{6} + dfrac{1}{4} - dfrac{3}{7} - dfrac{5}{12}
c. dfrac{11.3^{22}.3^7-9^{15}}{left(2.3^{14}right)^2}
d, dfrac{3}{2^2} . dfrac{8}{3^2} . dfrac{15}{4^2} ... dfrac{899}{30^2}
Bài 2: Tìm x biết:
a, 2x + 2x+1 + 2x+2 + 2 x+3 480
b, left(dfrac{1}{2}+dfrac{1}{3}+...+dfrac{1}{2012}+dfrac{1}{2013}right) . x dfrac{2012}{1}+dfrac{2011}{2}+dfrac{2010}{3}+...+dfrac{2}{2011}+dfrac{1}{2012}.
Đọc tiếp
Bài 1: Tính hợp lý:
a. 1152 - (374 + 1152) + (374 - 65)
b. \(\dfrac{7}{12}\) + \(\dfrac{5}{6}\) + \(\dfrac{1}{4}\) - \(\dfrac{3}{7}\) - \(\dfrac{5}{12}\)
c. \(\dfrac{11.3^{22}.3^7-9^{15}}{\left(2.3^{14}\right)^2}\)
d, \(\dfrac{3}{2^2}\) . \(\dfrac{8}{3^2}\) . \(\dfrac{15}{4^2}\) ... \(\dfrac{899}{30^2}\)
Bài 2: Tìm x biết:
a, 2x + 2x+1 + 2x+2 + 2 x+3 = 480
b, \(\left(\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{2012}+\dfrac{1}{2013}\right)\) . x = \(\dfrac{2012}{1}+\dfrac{2011}{2}+\dfrac{2010}{3}+...+\dfrac{2}{2011}+\dfrac{1}{2012}.\)
Bài 1. Chứng tỏ rằng: Bdfrac{1}{2^2}+dfrac{1}{3^2}+dfrac{1}{4^2}+dfrac{1}{5^2}+dfrac{1}{6^2}+dfrac{1}{7^2}+dfrac{1}{8^2} 1
Bài 2. so sánh : Adfrac{2011+2012}{2012+2013}
và Bdfrac{2011}{2012}+dfrac{2012}{2013}
Bài 3. Rút gọn : B left(1-dfrac{1}{1}right).left(1-dfrac{1}{3}right).left(1-dfrac{1}{4}right)...left(1-dfrac{1}{20}right)
Bài 4. Rút gọn biểu thức : A 1+dfrac{1}{2}+dfrac{1}{2^2}+dfrac{1}{2^3}+...+dfrac{1}{2^{2012}}
Bài 5. Tìm số nguyên pi...
Đọc tiếp
Bài 1. Chứng tỏ rằng: B=\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+\dfrac{1}{4^2}+\dfrac{1}{5^2}+\dfrac{1}{6^2}+\dfrac{1}{7^2}+\dfrac{1}{8^2}< 1\)
Bài 2. so sánh : A=\(\dfrac{2011+2012}{2012+2013}\)
và B=\(\dfrac{2011}{2012}+\dfrac{2012}{2013}\)
Bài 3. Rút gọn : B= \(\left(1-\dfrac{1}{1}\right).\left(1-\dfrac{1}{3}\right).\left(1-\dfrac{1}{4}\right)...\left(1-\dfrac{1}{20}\right)\)
Bài 4. Rút gọn biểu thức : A= \(1+\dfrac{1}{2}+\dfrac{1}{2^2}+\dfrac{1}{2^3}+...+\dfrac{1}{2^{2012}}\)
Bài 5. Tìm số nguyên \(\pi\) sao cho \(\pi+5\) chia hết cho \(\pi-2\)
HELP ME!!!! MÌNH TICK CHO HA
Tính rồi tìm số nghịch đảo của :
\(\dfrac{2}{3}.\dfrac{4}{5}.\dfrac{6}{7}.\dfrac{8}{9}.\dfrac{10}{11}.\dfrac{1}{2}.\dfrac{3}{4}.\dfrac{5}{6}.\dfrac{7}{8}.\dfrac{9}{10}\)
HA
24 tháng 7 2017 lúc 9:36
tính
a,\((15.\dfrac{3}{5}-19\dfrac{7}{9})-(13\dfrac{3}{5}-17\dfrac{7}{9})\)
b,\([\dfrac{6}{5}-(\dfrac{3}{7}-2\dfrac{1}{7})\div\dfrac{4}{7}].(-\dfrac{3}{5})+\dfrac{2}{3}\div(-\dfrac{5}{6})\)
giúp mình nhé
1. tìm x thuộc z biết dfrac{x}{-12}dfrac{-3}{2}
2 tính
a,dfrac{-7}{9}timesdfrac{6}{11}+dfrac{-2}{9}
b,dfrac{-4}{7}:2
c,115- (24-5times3)
d,dfrac{-3}{7}timesdfrac{5}{9}+dfrac{4}{9}timesdfrac{-3}{7}+2dfrac{3}{7}
e,dfrac{1}{4times5}+dfrac{1}{6times7}+......dfrac{1}{79times80}
Đọc tiếp
1. tìm x thuộc z biết \(\dfrac{x}{-12}\)=\(\dfrac{-3}{2}\)
2 tính
a,\(\dfrac{-7}{9}\times\dfrac{6}{11}+\dfrac{-2}{9}\)
b,\(\dfrac{-4}{7}:2=\)
c,115- (24-5\(\times\)3)
d,\(\dfrac{-3}{7}\times\dfrac{5}{9}+\dfrac{4}{9}\times\dfrac{-3}{7}+2\dfrac{3}{7}\)
e,\(\dfrac{1}{4\times5}+\dfrac{1}{6\times7}+......\dfrac{1}{79\times80}\)
BT2: Tính nhanh
13) \(\dfrac{4}{9}:\left(-\dfrac{1}{7}\right)+6\dfrac{5}{9}:\left(-\dfrac{1}{7}\right)\)
14) \(\left(-\dfrac{3}{4}+\dfrac{5}{13}\right):\dfrac{2}{7}-\left(2\dfrac{1}{4}+\dfrac{8}{13}\right):\dfrac{2}{7}\)
*Phép chia
a)\(11\dfrac{1}{4}-\left(2\dfrac{5}{7}+5\dfrac{1}{4}\right)\)
b)\(\left(8\dfrac{5}{11}+3\dfrac{5}{8}\right)-3\dfrac{5}{11}\)
c)\(\dfrac{-1}{4}.13\dfrac{9}{11}-0,25.6\dfrac{2}{11}\)
d)\(\dfrac{4}{9}:\left(\dfrac{-1}{7}\right)+6\dfrac{5}{9}:\left(\dfrac{-1}{7}\right)\)
Cho C= \(4+\dfrac{1}{7^6}+\dfrac{3}{7}+\dfrac{4}{7^2}+\dfrac{-441}{7^6}+\dfrac{27}{7^5}\)
D= \(\dfrac{147}{7^3}+4+\dfrac{35}{7^7}+\dfrac{4}{7^2}+\dfrac{27}{7^5}+\dfrac{-9}{7^9}\)
So sánh C với D
tìm x
\([\dfrac{6:\dfrac{3}{5}-1\dfrac{1}{16}.\dfrac{16}{7}}{4\dfrac{1}{5}-\dfrac{10}{11}+5\dfrac{2}{11}}-\dfrac{\left(\dfrac{3}{20}+\dfrac{1}{2}-\dfrac{1}{5}\right).\dfrac{12}{49}}{3\dfrac{1}{3}+\dfrac{2}{9}}].x=2\dfrac{23}{96}\)