Tính:
a,(\(\frac{-1}{3}\))\(^7\).3\(^7\)
b,(0,125)\(^3\).512
c,\(\frac{90^2}{15^2}\)
d,\(\frac{790^4}{79^4}\)
Tính :
a/ \(\left(\frac{-1}{3}\right)^7\cdot3^7\)
b/ \(\left(0,125\right)^3\cdot512\)
c/ \(\frac{90^2}{15^2}\)
d/ \(\frac{790^4}{79^4}\)
tính
a) -1 phần 3 mũ 7 nhân 3 mũ 7
b) 0,125 mũ 3 nhân 512
c) 90 mũ 2 phần 15 mũ 2
d)790 mũ 4 phần 79 mũ 4
tìm x
a) 2x - 1 = 16
b) (x-1) mũ 2 = 25
c)-1 phần 3 mũ 3 nhân x = 1 phần 81
toi ko co the bt day nh vau ko dau
bai1 tìm x : \(\frac{-64}{343}=x^3\)
\(\left(x-20\right)^{100}+|y+4|=0\)
(\(x-\frac{1}{2})^3=\frac{1}{27}\)
\(\left(x+\frac{1}{2}\right)^2=\frac{4}{25}\)
bai2 tinh: a) \(\frac{8^{14}}{4^{12}}\)
b)\(\left(\frac{-1}{3}\right)^7.3^7\)
c)\(\frac{90^2}{15^2}\)
d)\(\frac{790^4}{79^4}\)
Bài 2:
a) \(\frac{8^{14}}{4^{12}}\)
\(=\frac{\left(2^3\right)^{14}}{\left(2^2\right)^{12}}\)
\(=\frac{2^{42}}{2^{24}}\)
\(=2^{18}\)
\(=262144.\)
b) \(\left(-\frac{1}{3}\right)^7.3^7\)
\(=\left[\left(-\frac{1}{3}\right).3\right]^7\)
\(=\left(-1\right)^7\)
\(=-1.\)
c) \(\frac{90^2}{15^2}\)
\(=\left(\frac{90}{15}\right)^2\)
\(=6^2\)
\(=36.\)
d) \(\frac{790^4}{79^4}\)
\(=\left(\frac{790}{79}\right)^4\)
\(=10^4\)
\(=10000.\)
Chúc bạn học tốt!
Mk làm tiếp cho bạn Vũ Minh Tuấn nhé!
Bài 1:
\(-\frac{64}{343}=x^3\)
\(\Rightarrow x^3=\left(-\frac{4}{7}\right)^3\)
\(\Rightarrow x=-\frac{4}{7}\)
Vậy \(x=-\frac{4}{7}\)
\(\left(x+20\right)^{100}+\left|y+4\right|=0\)
Ta có: \(\left(x+20\right)^{100}\ge0;\left|y+4\right|\ge0\)
\(\Rightarrow\left\{{}\begin{matrix}\left(x+20\right)^{100}=0\\\left|y+4\right|=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=-20\\y=-4\end{matrix}\right.\)
Vậy \(x=-20;y=-4\)
\(\left(x-\frac{1}{2}\right)^3=\frac{1}{27}\)
\(\Rightarrow\left(x-\frac{1}{2}\right)^3=\left(\frac{1}{3}\right)^3\)
\(\Rightarrow x-\frac{1}{2}=\frac{1}{3}\)
\(\Rightarrow x=\frac{5}{6}\)
Vậy \(x=\frac{5}{6}\)
\(\left(x+\frac{1}{2}\right)^2=\frac{4}{25}\)
\(\Rightarrow\left(x+\frac{1}{2}\right)^2=\left(\frac{2}{5}\right)^2\)
\(\Rightarrow\left[{}\begin{matrix}x+\frac{1}{2}=\frac{2}{5}\\x+\frac{1}{2}=-\frac{2}{5}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-\frac{1}{10}\\x=-\frac{9}{10}\end{matrix}\right.\)
Vậy \(x\in\left\{-\frac{1}{10};-\frac{9}{10}\right\}\)
1) \(79\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}.\frac{7}{90}\)
2)\(\left(3\frac{1}{5}-\frac{1}{11}\right).11\)
3)\(4\frac{1}{5}:\left(2\frac{1}{3}.1\frac{2}{5}\right)\)
4)\(13,2.\frac{15}{64}-\left(\frac{4}{5}+\frac{2}{3}\right):3\frac{2}{3}\)
Tính :
a, ( 1/7 )7 . 77
b, ( 0,125)3 . 512
c, ( 0,25)4 . 1024
d, 903/ 153
e, 7904/ 794
f,32/ ( 0,375)2
mk sẽ tick cho
a) (1 / 7.7) 7 = 1
b) (0,125.8)3=1
c)( 0,25.0,25.32)2=22=4
d) (90/15) 3 = 6 3
) ( 790/79)4=104
f) (3/0,75)2=82
Bài 1: Tìm hai số x và y biết x : 2 = y : (-5) và x - y = -7
Bài 2: Tìm x, biết:
a) ( \(-\dfrac{1}{3}\))\(^3\) . x = \(\dfrac{1}{81}\)
Bài 3: Tính
a) (\(-\dfrac{1}{3}\))\(^7\) . 3\(^7\)
b) (0,125)\(^3\) . 512
c) \(\dfrac{90^2}{15^2}\)
d) \(\dfrac{790^4}{79^4}\)
Ta có dựa vào dãy tỉ số bằng nhau
1)\(\dfrac{x}{-5}=\dfrac{y}{2}=\dfrac{x-y}{-5-2}=1\)
suy ra x=-5 , y=2
2) bạ tự làm nhé
3)=\(\dfrac{-1}{3^7}.3^7=-1\)
b)=\(\dfrac{1}{512}.512=1\)
c)=\(\dfrac{90^2}{15^2}=2^2.3^2=36\)
d)=\(\dfrac{790^4}{79^4}=10^4=10000\)
Tick em nha
Tính:
a)\(0,75 - \frac{5}{6} + 1\frac{1}{2};\)
b)\(\frac{3}{7} + \frac{4}{{15}} + \left( {\frac{{ - 8}}{{21}}} \right) + \left( { - 0,4} \right);\)
c)\(0,625 + \left( {\frac{{ - 2}}{7}} \right) + \frac{3}{8} + \left( {\frac{{ - 5}}{7}} \right) + 1\frac{2}{3}\)
d)\(\left( { - 3} \right).\left( {\frac{{ - 38}}{{21}}} \right).\left( {\frac{{ - 7}}{6}} \right).\left( { - \frac{3}{{19}}} \right);\)
e) \(\left( {\frac{{11}}{{18}}:\frac{{22}}{9}} \right).\frac{8}{5};\)
g)\(\left[ {\left( {\frac{{ - 4}}{5}} \right).\frac{5}{8}} \right]:\left( {\frac{{ - 25}}{{12}}} \right)\)
a)
\(\begin{array}{l}0,75 - \frac{5}{6} + 1\frac{1}{2} = \frac{3}{4} - \frac{5}{6} + \frac{3}{2}\\ = \frac{9}{{12}} - \frac{{10}}{{12}} + \frac{{18}}{{12}} = \frac{{17}}{{12}}\end{array}\)
b)
\(\begin{array}{l}\frac{3}{7} + \frac{4}{{15}} + \left( {\frac{{ - 8}}{{21}}} \right) + \left( { - 0,4} \right) = \frac{3}{7} + \frac{4}{{15}} - \frac{8}{{21}} - \frac{2}{5}\\ = \left( {\frac{3}{7} - \frac{8}{{21}}} \right) + \left( {\frac{4}{{15}} - \frac{2}{5}} \right)\\ = \left( {\frac{9}{{21}} - \frac{8}{{21}}} \right) + \left( {\frac{4}{{15}} - \frac{6}{{15}}} \right)\\ = \frac{1}{{21}} + \left( {\frac{{ - 2}}{{15}}} \right)\\ = \frac{5}{{105}} - \frac{{14}}{{105}}\\ = \frac{{ - 9}}{{105}} = \frac{{ - 3}}{{35}}\end{array}\)
c)
\(\begin{array}{l}0,625 + \left( {\frac{{ - 2}}{7}} \right) + \frac{3}{8} + \left( {\frac{{ - 5}}{7}} \right) + 1\frac{2}{3}\\ = \frac{5}{8} + \left( {\frac{{ - 2}}{7}} \right) + \frac{3}{8} - \frac{5}{7} + \frac{5}{3}\\ = \left( {\frac{5}{8} + \frac{3}{8}} \right) + \left( {\frac{{ - 2}}{7} - \frac{5}{7}} \right) + \frac{5}{3}\\ = 1 - 1 + \frac{5}{3} = \frac{5}{3}\end{array}\)
d)
\(\begin{array}{l}\left( { - 3} \right).\left( {\frac{{ - 38}}{{21}}} \right).\left( {\frac{{ - 7}}{6}} \right).\left( { - \frac{3}{{19}}} \right)\\ = \frac{{ - 3.\left( { - 38} \right).\left( { - 7} \right).\left( { - 3} \right)}}{{21.6.19}}\\ = \frac{{3.38.7.3}}{{21.6.19}}\\ = \frac{{3.2.19.7.3}}{{3.7.3.2.19}}\\ = 1\end{array}\)
e)
\(\begin{array}{l}\left( {\frac{{11}}{{18}}:\frac{{22}}{9}} \right).\frac{8}{5} = \left( {\frac{{11}}{{18}}.\frac{9}{{22}}} \right).\frac{8}{5}\\ = \frac{{11.9.4.2}}{{9.2.2.11.5}} = \frac{2}{5}\end{array}\)
g)
\(\left[ {\left( {\frac{{ - 4}}{5}} \right).\frac{5}{8}} \right]:\left( {\frac{{ - 25}}{{12}}} \right) = \frac{{ - 20}}{{40}}:\left( {\frac{{ - 25}}{{12}}} \right)\\ = \frac{{ - 1}}{2}.\frac{{ - 12}}{{25}} = \frac{6}{{25}}\)
1. Tính:a) A=1253.24; b) B=\(\frac{1}{49^4}\).77; c) C=\(\frac{27^3+9^5}{81^3+3^{11}}\); d) D=\(\frac{\frac{4}{9}+\frac{28}{15}-\frac{12}{4}}{\frac{5}{9}+\frac{35}{15}-\frac{15}{4}}\)
2. a) Tìm GTNN của A= (2x-3)2-7; b) Tìm GTLN của 3- giá trị tuyệt đối của 3x-2
3. Tìm sốx nguyên để các số sau là số nguyên: a)A= 2+\(\frac{3}{x+1}\);b) B=\(\frac{3x-1}{x-1}\)
Tính:
\(a) \frac{790^4}{79^4} \)
\(b) \frac{3^2}{0,375^2} \)
\( c) 3^2.\frac{1}{243}.81^2.\frac{1}{3^3} \)
\( d) (4.2^5):(2^3.\frac{1}{16})\)
a) \(\frac{790^4}{79^4}=\frac{79^4.10^4}{79^4}=10^4=10000\)
b) \(\frac{3^2}{0,375^2}=\frac{0,375^2.8^2}{0,375^2}=8^2=64\)
c) \(3^2.\frac{1}{243}.81^2.\frac{1}{3^3}=3^2.3^{-5}.3^8.3^{-3}=3^2=9\)
d) \(\left(4.2^5\right):\left(2^3.\frac{1}{16}\right)=2^7:\left(2^3.2^{-4}\right)=2^7:2^{-1}=2^7:\frac{1}{2}=2^8\)