\(\dfrac{1}{2}\cdot\left(\dfrac{2}{9}+\dfrac{3}{7}-\dfrac{5}{27}\right)\\ =\dfrac{1}{2}\left(\dfrac{3}{7}+\dfrac{1}{27}\right)\\ =\dfrac{1}{2}\cdot\dfrac{88}{189}\\ =\dfrac{44}{189}\)
Câu trả lời:
a)2/3+1/5.10/7
b)17/18-11/6
c)7/12-27/7.1/18
d)3/10.(-5/6)-1/8
e)(-4/9).3/8+1/8
f)2/7+28/27:(-4/9)
g)(1/2-2/3).4/5
h)9/7.(3/7-1/2)
a) -3 phần 5x + -7 phần 4 = 3 phần 10 b)(x- 7 phần 18) × 15 phần 27 = -10 phần 27 c) (2x + 3 phần 4 ) ÷ 2 phần 3 = 5 phần 8 d) 5 1 phần 3 × (x + 9 phần 4 ) =-10 2 phần 3
Tính hợp lí nếu có thể
a)1/2.(2/9+3/7-5/27)
b)1/2+3/4-(3/4-4/5)
c)1/3.5/7-7/27.36/14
Cho:
\(A=4+\frac{1}{7^6}+\frac{3}{7}+\frac{4}{7^2}+\frac{-441}{7^6}+\frac{27}{7^5}\)
\(B=\frac{147}{7}+4+\frac{35}{7^7}+\frac{4}{7^2}+\frac{27}{7^5}+\frac{-9}{7^9}\)
Hãy so sánh A với B
tim x:
1)x-10/3=7/15*3/5
2)8/23.46/24*x=1/3
3)x+3/22=27/121*11/9
4)1-x=49/65*5/7
a. 19+(29-9*37)-(63*9-29*99)
b.1/2+1/4+1/8+1/16+1/32+1/64+1/128
c. 5*4^15*9^9-4*3^20*8^9
____________________________
5*2^9*6^19-7*2^29*27^6
ý c la phan số nhé
Bài 15:
a)\(\dfrac{-2}{5}\)+\(\dfrac{4}{5}\) . x =\(\dfrac{3}{5}\)
b)\(\dfrac{-3}{7}\) - \(\dfrac{4}{7}\):x = -2
Bài 16
a) x - \(\dfrac{10}{3}\) = \(\dfrac{7}{15}\) . \(\dfrac{3}{5}\)
b) x + \(\dfrac{3}{22}\)= \(\dfrac{27}{121}\) . \(\dfrac{11}{9}\)
c) \(\dfrac{8}{23}\) . \(\dfrac{48}{24}\) - x = \(\dfrac{1}{3}\)
d) 1 - x = \(\dfrac{49}{65}\).\(\dfrac{5}{7}\)
Bài 17: tìm x
a) \(\dfrac{62}{7}\) . x = \(\dfrac{29}{9}\): \(\dfrac{3}{56}\)
b) \(\dfrac{1}{5}\) : x=\(\dfrac{1}{5}\)+\(\dfrac{1}{7}\)
bài 18:
a)\(\dfrac{2}{5}\)+\(\dfrac{3}{4}\): x =\(\dfrac{-1}{2}\)
b)\(\dfrac{5}{7}\) - \(\dfrac{2}{3}\) . x = \(\dfrac{4}{5}\)
c) \(\dfrac{1}{2}\)x + \(\dfrac{3}{5}\)x = \(\dfrac{-2}{3}\)
d) \(\dfrac{4}{7}\).x-x = \(\dfrac{-9}{14}\)
bài 19: tính
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+\(\dfrac{1}{3.4}\)+...+ \(\dfrac{1}{2018.2019}\)
bài 20:tìm x
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+...+\(\dfrac{1}{x.\left(x+1\right)}\)=\(\dfrac{2008}{2009}\)
bài 21: tìm x
\(\dfrac{x+1}{99}\)+\(\dfrac{x+2}{98}\)\(\dfrac{x+3}{97}\)\(\dfrac{x+4}{96}\)=-4
bài 22 : so sánh các phân số sau:
a) \(\dfrac{-1}{5}\)+\(\dfrac{4}{-5}\)và 1
b) \(\dfrac{3}{5}\) và \(\dfrac{2}{3}\)+\(\dfrac{-1}{5}\)
c)\(\dfrac{3}{2}\)+\(\dfrac{-4}{3}\) và \(\dfrac{1}{10}\)+\(\dfrac{-4}{5}\)
d) \(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{5}\)+\(\dfrac{1}{6}\) và 2
x=1/4+2/13
x/3=2/3+-1/7
-8/3+1/3<x<-2/7+-5/7
-5/6 +8/3+29/-6=<x>=-1/2+2+5/2
1/6+2/5
3/5+-7/4
4/13+-12/30
-3/29+16/58
8/40+-36/45
-8/18+15/27
c) 4/9*(5/7+2/5)-4/9*(-2/7+7/5) /////////d) (67/111+2/33-15/117)*(1/3-1/4-1/12) Giúp mk vs ạ
