tính
a)1/1/24*5*2/5*2
b)2/3/13*26/58*4*2/15/24*8/21
tính:
\(2\dfrac{3}{13}\) x \(\dfrac{26}{58}\) x 4 x \(2\dfrac{15}{24}\) x \(\dfrac{8}{21}\)
\(=\dfrac{29}{13}\cdot\dfrac{13}{29}\cdot4\cdot\dfrac{21}{8}\cdot\dfrac{8}{21}=4\)
tính:
\(2\dfrac{3}{13}\) x \(\dfrac{26}{58}\) x 4 x \(2\dfrac{15}{24}\) x \(\dfrac{8}{21}\)
bài này mik ra \(\dfrac{39}{29}\) ko bt đúng ko :)
-12/18 + (-21)/35
-3/21 + 6/42
-18/24 + 15/21
1/6 + 2/5
3/5 + (-7)/4
(-2) + (-5)/8
1/-8 + (-5)/9
4/13 + 12/39
1/21 + 1/28
-3/29 + 16/58
8/40 + (-36)/45
-8/18 + (-15)/27
13/30 + (-1)/5
2/21 + 1/28
5 + (-3)/4
18/24 + 45/-10
câu 1)
\(\dfrac{-12}{18}+\left(\dfrac{-21}{35}\right)=\dfrac{-19}{15}\)
câu 2)
\(-\dfrac{3}{21}+\dfrac{6}{42}=0\)
câu 3)
\(-\dfrac{18}{24}+\dfrac{15}{21}=-\dfrac{1}{28}\)
câu 4)
\(\dfrac{1}{6}+\dfrac{2}{5}=\dfrac{17}{30}\)
câu 5)
\(\dfrac{3}{5}+\left(-\dfrac{7}{4}\right)=-\dfrac{23}{20}\)
câu 6)
\(\left(-2\right)+\left(\dfrac{-5}{8}\right)=\dfrac{-21}{8}\)
câu 7)
\(\dfrac{1}{-8}+\left(-\dfrac{5}{9}\right)=-\dfrac{49}{72}\)
câu 8)
\(\dfrac{4}{13}+\dfrac{12}{39}=\dfrac{8}{13}\)
câu 9)
\(\dfrac{1}{21}+\dfrac{1}{28}=\dfrac{1}{12}\)
câu 10)
\(-\dfrac{3}{29}+\dfrac{16}{58}=\dfrac{5}{29}\)
câu 11)
\(\dfrac{8}{40}+\left(-\dfrac{36}{45}\right)=-\dfrac{3}{5}\)
câu 12)
\(-\dfrac{8}{18}+\left(-\dfrac{15}{27}\right)=-1\)
câu 13)
\(\dfrac{13}{30}+\left(-\dfrac{1}{5}\right)=\dfrac{7}{30}\)
câu 14)
\(\dfrac{2}{21}+\dfrac{1}{28}=\dfrac{11}{84}\)
câu 15)
\(5+\left(-\dfrac{3}{4}\right)=\dfrac{17}{4}\)
câu 16)
\(\dfrac{18}{24}+\dfrac{45}{-10}=-\dfrac{15}{4}\)
3.(-4)^2+2.(-5)-20
(-54)+(+39)-(+10)+(-85
5.(3)^2-14.(-8)+(-40)
(-24)+(-30)-(-40)
31-[26-(209+26)]
29-(-25)+(+40)
231+26-(209+26) BÀI TẬP TẾT NHIỀU QUÁ MONG MN
215+(-38)-(-58)+90-85 GIÚP ĐỠ THANK..........
21+22+23+24-11-12-13-14
215+(-38)-(-58)-(-58)-15
Tính :
2/5 + 11/15 =
7/8 - 7/9 =
11/13 x 26/31 =
16/24 : 4 =
30 : 6/5 =
9/16 : 4 =
1/2 : 1/3 x 8/15 =
\(\dfrac{2}{5}+\dfrac{11}{15}=\dfrac{6}{15}+\dfrac{11}{15}=\dfrac{17}{15}\)
\(\dfrac{7}{8}-\dfrac{7}{9}=\dfrac{63}{72}-\dfrac{56}{72}=\dfrac{7}{72}\)
\(\dfrac{11}{13}\times\dfrac{26}{31}=\dfrac{22}{31}\)
\(\dfrac{16}{24}:4=\dfrac{16}{24}\times\dfrac{1}{4}=\dfrac{4}{24}=\dfrac{1}{6}\)
\(30:\dfrac{6}{5}=30\times\dfrac{5}{6}=25\)
\(\dfrac{9}{16}:4=\dfrac{9}{16}\times\dfrac{1}{4}=\dfrac{9}{64}\)
\(\dfrac{1}{2}:\dfrac{1}{3}\times\dfrac{8}{15}=\dfrac{1}{2}\times3\times\dfrac{8}{15}=\dfrac{4}{5}\)
2/5 + 11/15 = 17/15
7/8 - 7/9 = 7/72
11/13 x 26/31 = 22/31
16/24 : 4 = 1/6
30 : 6/5 = 25
9/16 : 4 = 9/64
1/2 : 1/3 x 8/15 = 3/2 x 8/15 = 4/5
Bài 1 Tính nhanh
a) -3/7 + 5/13 + 3/7
b) -5/21+-2/21+8/24
c) -5/11+(-6/11+2)
d) (-1/32+1/2)+15/32
e)5/17+ -6/13 + 3/4 + 7/-13+12/17
f) 7/23+-18/18+-4/9+16/23+-5/8
g)1/3+-3/4+3/5+-1/36+1/15+-2/9
h)-1/2+1/3+-1/4+-2/8+4/18+4/9
a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\)
=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\)
=\(0+\dfrac{5}{13}\)
=\(\dfrac{5}{13}\)
hãy tính nhanh:
A.1+2+3+4+5+6+7+8+9+10+11+12+13-14=?
B.30-29+28-27+26-25+24-23+22-21...+12-11+10-9+8-7+6-5+4-3+2-1=?
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26=?
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26=351
Số số hạng của dãy số là:
(26-1):1+1=26 (số)
Tổng của dãy số là:
(26+1)*26:2=351
Đáp số 351
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26
ta co so so hang ;;: 26-1:1+1= 26 so so hang
ta co tong bang (26+1).26:2=351
Đáp số 351
Minh thu lai roi chac chan luon . k nha .Thank!