a/ 596,79+327.69-476.79
b/ 0.7*17.4*4+0.28*540+29*2.8
c/ 1/1/5*7/8+1.2*1/8-0.2
d/ 15/35+16/28-7/35-12/15
-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)
\(\dfrac{18}{24}+\dfrac{45}{-10}=-\dfrac{15}{4}\)
tính bằng cách hợp lí nếu có thể
a 5/7 x 9/11 + 5/7 x 2/11 - 5/7
b 15/35 + ( 16/28 - 7/35 ) + 12/15
c 15/35 + 16/28 - 7/35 - 12/15
d 3/1/4 x ( 1/1/2 - 1 ) + 2,5 - 1/2 )
Tính hợp lý
a, - ( - 15 ) - ( +27 ) + ( + 27 ) + ( -15 ) + ( -29)
b, 12 - ( a + 105 - 13 ) + ( 4 + 105 - 13 )
c, ( 5 + 7 - 8 ) - ( 7 + 5 - 8 )
d, - 15 - ( -17 + 21 - 35 ) + ( -17 + 21 - 35)
e, 32 - ( -7 - 28 + 15 ) - ( 7 + | -28 | + 32 )
f, -1379 - ( -1379 - 27 )
Làm giùm, cần gấp.
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+27+28+29+30+31+32+33+34+35+36+37=
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+27+28+29+30+31+32+33+34+35+36+37
=(1+37)x37:2
=703
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+149+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39*100
a. ( 19 5/8 : 7/12 - 13 1/4 : 7/12) . 4/5
b.( - 2/5 + 3/7) - (4/9 + 12/20 - 13/35) + 7/35
c. ( 4 5/57 - 3/ 4/51 + 8 13/29) - ( 3 5/57 - 6 16/29)
\(\left(19\frac{5}{8}:\frac{7}{12}-13\frac{1}{4}:\frac{7}{12}\right).\frac{4}{5}\)
\(=\left(\frac{157}{8}:\frac{7}{12}-\frac{53}{4}:\frac{7}{12}\right).\frac{4}{5}\)
\(=\left[\left(\frac{157}{8}-\frac{53}{4}\right):\frac{7}{12}\right].\frac{4}{5}\)
\(=\left[\frac{51}{8}:\frac{7}{12}\right].\frac{4}{5}\)
\(=\frac{153}{14}.\frac{4}{5}\)
\(=\frac{306}{35}\)
\(\left(\frac{-2}{5}+\frac{3}{7}\right)-\left(\frac{4}{9}+\frac{12}{20}-\frac{13}{35}\right)+\frac{7}{35}\)
\(=\frac{1}{35}-\frac{212}{315}+\frac{7}{35}\)
\(=\frac{1}{35}+\frac{-212}{315}+\frac{7}{35}\)
\(=\frac{9}{315}+\frac{-212}{315}+\frac{63}{315}\)
\(=\frac{-140}{315}=\frac{-4}{9}\)
\(\left(4\frac{5}{57}-3\frac{4}{51}+8\frac{13}{29}\right)-\left(3\frac{5}{57}-6\frac{16}{29}\right)\)
\(=\left(\frac{233}{57}-\frac{157}{51}+\frac{245}{29}\right)-\left(\frac{176}{57}-\frac{190}{29}\right)\)
\(=\frac{1941}{323}-\frac{-5726}{1653}\)
\(=\frac{14011}{1479}\)
tính :
1+2+3+4+5+6+7+8+9+10+12+14+16+18+20+23+26+29+30-29-19-9+50+55+15+25+35+45+65+75+85+95+1000000000000+99999999=?
dãy số dài như thế này dễ lẫn lắm bạn ạ
a ) - 8 / 24 + - 4 / 12
b ) - 20 / 35 + 16 / 24
c ) - 3 / 9 + - 6 / 15
d ) 3 / 13 - 4 / 10
e ) 5 / 17 - 9 / 15
g ) 9 / 18 - 6 / 15 + 3 / - 9
h ) 5 / 4 - 1 / 2 + - 7 / 8
câu a :
\(\dfrac{-8}{24}+\dfrac{-4}{12}=\dfrac{-1}{3}+\dfrac{-1}{3}=\dfrac{-2}{3}\)
câu b :
\(\dfrac{-20}{35}+\dfrac{16}{24}=\dfrac{-4}{7}+\dfrac{2}{3}=\dfrac{2}{21}\)
câu c :
\(\dfrac{-3}{9}+\dfrac{-6}{15}=\dfrac{-1}{3}+\dfrac{-2}{5}=\dfrac{-11}{15}\)
câu d :
\(\dfrac{3}{13}-\dfrac{4}{10}=\dfrac{3}{13}-\dfrac{2}{5}=\dfrac{-11}{65}\)
câu e :
\(\dfrac{5}{17}-\dfrac{9}{15}=\dfrac{5}{17}-\dfrac{3}{5}=\dfrac{-26}{85}\)
câu g :
\(\dfrac{9}{18}-\dfrac{6}{15}+\dfrac{3}{-9}=\dfrac{9}{18}-\dfrac{6}{15}+\dfrac{-3}{9}\\ =\dfrac{1}{2}-\dfrac{2}{5}+\dfrac{-1}{3}=\dfrac{-7}{30}\)
câu h :
\(\dfrac{5}{4}-\dfrac{1}{2}+\dfrac{-7}{8}=\dfrac{10}{8}-\dfrac{4}{8}+\dfrac{-7}{8}=\dfrac{-1}{8}\)