Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a, 102 . 32 + 53
= 100 . 9 . 125
= 900 . 125
= 112.500
b, 124 : 123 + 73 : 7
= 124-3 + 73-1
= 12 + 72
= 12 + 49
= 61
c, ( 21 + 19 )4 : 402 + 31 - 1600
= 404 : 402 + 31 - 1600
= 402 + 31 - 1600
= 1600 + 31 - 1600
= ( 1600 - 1600 ) + 31
= 0 + 31
= 31
d, ( 572 - 72 )2 + 33 . 2 - 20 000
= 5002 + 27 . 2 - 20 000
= 25 000 + 54 - 20 000
= 25 054 + 20 000
= 5 054
Đây bạn nhé!!!
Học tốt nhé!!!
a: =6/16-7/16-8/16=-9/16
b: =3/5(4/7+5/7-2/7)=3/5
c: =12+9/16+16+3/25-9-3/25+5+7/16
=26+1=27
\(=\dfrac{2^{19}\cdot3^9\cdot5+2^{18}\cdot3^9\cdot5}{2^{19}\cdot3^9-2^{20}\cdot3^{10}}\)
\(=\dfrac{2^{18}\cdot3^9\cdot5\left(2+1\right)}{2^{19}\cdot3^9\left(1-2\cdot3\right)}=\dfrac{1}{2}\cdot\dfrac{5\cdot3}{-5}=-\dfrac{3}{2}\)
\(A=\dfrac{2^{19}\cdot27^3\cdot5-15\cdot\left(-4\right)^9\cdot9^4}{6^9\cdot2^{10}-\left(-12\right)^{10}}\)
\(A=\dfrac{2^{19}\cdot\left(3^3\right)^3\cdot5-3\cdot5\cdot-\left(2^2\right)^9\cdot\left(3^2\right)^4}{2^9\cdot3^9\cdot2^{10}-\left(2^2\right)^{10}\cdot3^{10}}\)
\(A=\dfrac{2^{19}\cdot3^9\cdot5+3^9\cdot2^{18}\cdot5}{2^{19}\cdot3^9-2^{20}\cdot3^{10}}\)
\(A=\dfrac{2^{18}\cdot3^9\cdot5\cdot\left(2+1\right)}{2^{19}\cdot3^9\cdot\left(1-2\cdot3\right)}\)
\(A=\dfrac{1\cdot1\cdot5\cdot3}{2\cdot1\cdot-5}\)
\(A=-\dfrac{1}{2}\cdot3\)
\(A=-\dfrac{3}{2}\)
\(-\dfrac{4}{5}+2x=\dfrac{1}{3}-\dfrac{2}{3}x\\ \Leftrightarrow-\dfrac{4}{5}+2x-\dfrac{1}{3}+\dfrac{2}{3}x=0\\ \Leftrightarrow-\dfrac{17}{15}+\dfrac{8}{3}x=0\\ \Leftrightarrow\dfrac{8}{3}x=\dfrac{17}{15}\\ \Leftrightarrow x=\dfrac{17}{40}\)
=>8/3x=1/3+4/5=5/15+12/15=17/15
=>x=17/15:8/3=17/15x3/8=51/120=17/40
2.
a. \(\dfrac{-4}{9}\) . \(\dfrac{7}{15}+\dfrac{4}{-9}.\dfrac{8}{15}\) = \(\dfrac{-4}{9}.\left(\dfrac{7}{15}+\dfrac{8}{15}\right)\) = \(\dfrac{-4}{9}\) . 1 = \(\dfrac{-4}{9}\)
b. \(\dfrac{5}{-4}.\dfrac{16}{25}+\dfrac{-5}{4}.\dfrac{9}{25}\) = \(\dfrac{-5}{4}.\left(\dfrac{16}{25}+\dfrac{6}{25}\right)\) = \(\dfrac{-5}{4}.1\) = \(\dfrac{-5}{4}\)
c. \(4\dfrac{11}{23}-\dfrac{9}{14}+2\dfrac{12}{23}-\dfrac{5}{4}\) = \(\left(4\dfrac{11}{23}+2\dfrac{12}{23}\right)\) \(-\dfrac{9}{14}-\dfrac{5}{4}\) = \(\dfrac{68}{23}-\dfrac{9}{14}-\dfrac{5}{4}\) = \(\dfrac{745}{322}\) - \(\dfrac{5}{4}=\dfrac{685}{644}\)
d. \(2\dfrac{13}{27}-\dfrac{7}{15}+3\dfrac{14}{27}-\dfrac{8}{15}\) = \(\left(2\dfrac{13}{27}+3\dfrac{14}{27}\right)\) - \(\left(\dfrac{7}{15}-\dfrac{8}{15}\right)\) = \(\dfrac{68}{27}\) - \(\dfrac{-1}{15}\) =
e. \(11\dfrac{1}{4}-\left(2\dfrac{7}{5}+5\dfrac{1}{4}\right)\) = \(11\dfrac{1}{4}\) - \(\dfrac{81}{20}\) = \(\dfrac{-13}{10}\)
g. \(\dfrac{7}{19}.\dfrac{8}{11}+\dfrac{7}{19}.\dfrac{3}{11}+\dfrac{12}{19}\) = \(\dfrac{7}{9}.\left(\dfrac{8}{11}+\dfrac{3}{11}\right)+\dfrac{12}{19}\) = \(\dfrac{7}{9}.1+\dfrac{12}{19}\) = \(\dfrac{7}{19}+\dfrac{12}{19}\) = \(1\)
Bài 1:
a: \(\Leftrightarrow-10< 3x< -7\)
=>3x=-9
hay x=-3
b: \(\Leftrightarrow-9< 2x< -6\)
=>2x=-8
hay x=-4
\(\Leftrightarrow\dfrac{35+9}{105}< \dfrac{x}{210}< \dfrac{12}{21}-\dfrac{10}{21}+\dfrac{7}{21}\)
\(\Leftrightarrow88< x< 90\)
hay x=89