`#3107.101107`
1.
`a,`
`2 - 2/3 + 2,5 + 1/3 + 3 + 1/2`
`= (2 + 2,5 + 3) - (2/3 - 1/3 - 1/2)`
`= 7,5 - (-1/6)`
`= 7,5 + 1/6`
`= 23/3`
`b,`
`9/10 - (6/5 * 3/2 + 7/4)`
`= 9/10 - (18/10 + 7/4)`
`= 9/10 - 18/10 - 7/4`
`= -9/10 - 7/4`
`= -53/20`
Bài 1 : Thực hiện phép tính
a/ \(\dfrac{7}{6}\) - \(\dfrac{13}{12}\) + \(\dfrac{3}{4}\)
b/ 1 \(\dfrac{1}{2}\) . \(\dfrac{-4}{5}\) + \(\dfrac{3}{10}\)
c/ \(\dfrac{25}{9}\) . \(\dfrac{3}{10}\) + ( \(\dfrac{-5}{3}\) )\(^2\) . \(\dfrac{7}{10}\) + | \(\dfrac{-25}{3}\) |
Bài 2 : Tìm x , biết
a/ x - \(\dfrac{5}{6}\) = \(\dfrac{1}{4}\)
b/ \(\dfrac{26}{x}\) = \(\dfrac{-13}{-15}\)
( Cần gấp )
Bài 4: tìm x:
a) \(\dfrac{4}{3}\) + (1,25 - x) = 2,25
b) \(\dfrac{17}{6}\) - (x - \(\dfrac{7}{6}\) ) = \(\dfrac{7}{4}\)
c) 4 - (2x + 1) = 3 - \(\dfrac{1}{3}\)
bài 15:
a) (\(\dfrac{-2}{3}\))9 : x = (\(\dfrac{-2}{3}\))
b) x : (\(\dfrac{4}{9}\))5 = (\(\dfrac{4}{9}\))4
c) (x + 4)3 = -125
d) (10 - 5x)3 = 64
e) (4x + 5)2 = 81
Bài 16:
a) 4 - \(1\dfrac{2}{5}\) - \(\dfrac{8}{3}\)
b) -0,6 - \(\dfrac{-4}{9}\) - \(\dfrac{16}{15}\)
c) \(-\dfrac{15}{4}\) . (\(\dfrac{-7}{15}\)) . (\(-2\dfrac{2}{5}\)
Gi ải gấp giúp mình ạ, mình rất cần gấp
Tìm x :
1) \(\left(-0,75x+\dfrac{5}{2}\right).\dfrac{4}{7}-\left(-\dfrac{1}{3}\right)=-\dfrac{5}{6}\)
2) \(\left(4x-9\right)\left(2,5+\dfrac{-7}{3}x\right)=0\)
3) \(\left|x-\dfrac{3}{4}\right|-\dfrac{1}{2}=0\)
4)\(\left(\dfrac{3}{5}-\dfrac{2}{3}x\right)^3=\dfrac{-64}{125}\)
tính
a,\(6\dfrac{4}{5}-\left(1\dfrac{2}{3}+3\dfrac{4}{5}\right)\)
b,\(7\dfrac{5}{9}-\left(2\dfrac{3}{4}+3\dfrac{5}{9}\right)\)
c,\(6\dfrac{7}{7}-\left(1\dfrac{3}{4}+2\dfrac{5}{7}\right)\)
1,\(\dfrac{3}{16}\)- ( x - \(\dfrac{5}{4}\) ) - ( \(\dfrac{3}{4}\) + \(\dfrac{-7}{8}\) - 1 ) = \(2\dfrac{1}{2}\)
2,\(\dfrac{1}{2}\) . ( \(\dfrac{1}{6}\) - \(\dfrac{9}{10}\) ) = \(\dfrac{1}{5}\) - x + ( \(\dfrac{1}{15}\) - \(\dfrac{-1}{5}\) )
Giúp mik nhanh với ạ .
Thực hiện phép tính (hợp lí nếu có thể):
a) \(13\dfrac{2}{7}\) : (\(\dfrac{-8}{9}\)) + \(2\dfrac{5}{7}\) : (\(\dfrac{-8}{9}\))
b) (\(\dfrac{-6}{11}\)) . \(\dfrac{7}{10}\) . (\(\dfrac{11}{-6}\)) . (-20)
c) (\(-1\dfrac{1}{2}\)) : \(\dfrac{3}{4}\) . (\(-4\dfrac{1}{2}\))
Thực hiện phép tính (hợp lí nếu có thể):
a) (\(\dfrac{-6}{11}\)) . \(\dfrac{7}{10}\) . \(\dfrac{11}{-6}\) . (-20)
b) (\(-1\dfrac{1}{2}\)) : \(\dfrac{3}{4}\) . \(-4\dfrac{1}{2}\))
c) \(13\dfrac{2}{7}\) : (\(\dfrac{-8}{9}\)) + \(2\dfrac{5}{7}\) : (\(\dfrac{-8}{9}\))
Tính giá trị của các biểu thức sau 1) \(A=1+2+2^2+...+2^{2015}\) 2) \(B=\left(\dfrac{1}{4}-1\right)\cdot\left(\dfrac{1}{9}-1\right)\cdot\left(\dfrac{1}{16}-1\right)\cdot\cdot\cdot\cdot\cdot\left(\dfrac{1}{400}-1\right)\) 3) \(C=\left(\dfrac{1}{4\cdot9}+\dfrac{1}{9\cdot14}+\dfrac{1}{14\cdot19}+...+\dfrac{1}{44\cdot49}\right)\cdot\dfrac{1-3-5-7-...-49}{89}\) 4) \(D=\dfrac{2^{12}\cdot3^5-4^6\cdot9^2}{\left(2^2\cdot3\right)^6+8^4\cdot3^5}-\dfrac{5^{10}\cdot7^3-25^5\cdot49^2}{\left(125\cdot7\right)^3+5^9\cdot14^3}\) 5) \(E=\dfrac{\dfrac{1}{2003}+\dfrac{1}{2004}-\dfrac{1}{2005}}{\dfrac{5}{2003}+\dfrac{5}{2004}-\dfrac{5}{2005}}-\dfrac{\dfrac{2}{2002}+\dfrac{2}{2003}-\dfrac{2}{2004}}{\dfrac{3}{2002}+\dfrac{3}{2003}-\dfrac{3}{2004}}\) 6) Cho 13+23+...+103=3025 Tính S= 23+43+63+...+203
bài 2: 1, \(\left(\dfrac{5}{6}\right)^{10}.\left(\dfrac{3}{10}\right)^{10}\)2,\(\left(\dfrac{4}{7}\right)^{19}:\left(\dfrac{-12}{35}\right)^{19}\) 3,\(\left(\dfrac{-3}{7}\right)^7:\left(\dfrac{-3}{5}\right)\)
