a: -3/4=-0,75; 2/5=0,4
Vì -0,75<-0,2<0
và 0<0,4=0,4
nên -0,75<-0,2<0,4=0,4
=>\(-\frac34<-0,2<0,4=\frac25\)
b: -7/2=-3,5; 4/3>1>0,75
Vì \(-3,5<-0,5<0;0<0,75<1<\frac43\)
nên \(-3,5<-0,5<0,75<\frac43\)
=>\(-\frac72<-0,5<0,75<\frac43\)
Nhiều thế. Chị Ốc là cung Thiên Bình đấy. Anh BQ Thành là cung Ma Kết.
7 +1 + 2 + 6 + 4 + 7 + 3
= ( 7 +3 ) + ( 6 + 4 ) + ( 1 + 2 + 7 )
= 10 + 10 + 10 / = 10 x3
= 20 + 10 =30
= 30
a) \(\frac{2}{9}+\frac{1}{5}+\frac{7}{9}+\frac{4}{5}=\left(\frac{2}{9}+\frac{7}{9}\right)+\left(\frac{1}{5}+\frac{4}{5}\right)= 1+1=2 \)
b) \(\frac{19}{37}+\left(1+\frac{19}{37}\right)=\left(\frac{19}{37}-\frac{19}{37}\right)+1=0+1=1\)
c) \(\frac{9}{8}-\left(\frac{17}{7}-\frac{3}{7}\right)+\frac{7}{8}=\frac{9}{8}+\frac{7}{8}-\left(\frac{17}{7}-\frac{3}{7}\right)=2-2=0\)
d) \(\frac{3}{5}\times\frac{8}{27}\times\frac{5}{3}=\frac{3}{5}\times\frac{5}{3}\times\frac{8}{27}=1\times\frac{8}{27}=\frac{8}{27}\)
e) \(\frac{7}{19}\times\frac{1}{3}+\frac{7}{19}\times\frac{2}{3}=\frac{7}{19}\times\left(\frac{1}{3}+\frac{2}{3}\right)=\frac{7}{19}\times1=\frac{7}{19}\)
f) \(\frac{12}{5}\times4-4\times\frac{7}{5}=4\times\left(\frac{12}{5}-\frac{7}{5}\right)=4\times1=4\)
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\(a,\left(\frac{3}{4}+\frac{3}{2}\right):\frac{7}{4}-\frac{3}{4}\)
\(=\left(\frac{3}{4}+\frac{6}{4}\right).\frac{4}{7}-\frac{3}{4}\)
\(=\frac{9}{4}.\frac{4}{7}-\frac{3}{4}\)
\(=\frac{9}{7}-\frac{3}{4}\)
\(=\frac{36}{28}-\frac{21}{28}\)
\(=\frac{15}{28}\)
\(b,\left(-5\right)^2.\frac{7}{45}-\left(-5\right)^2.\frac{11}{45}\)
\(=\left(-5\right)^2.\left(\frac{7}{45}-\frac{11}{45}\right)\)
\(=\left(-5\right)^2.\frac{-4}{45}\)
\(=25.\frac{-4}{45}\)
\(=\frac{-100}{45}\)
\(=\frac{20}{9}\)
#Chúc em học tốt
1 + 2 + 3 + 4 + 5+ 6 + 7 + 8 + 9 = 45
lấy các số chẵn cộng lại vs nhau
\(1+2+3+4+5+6+7+8+9\)
\(=\left(1+9\right)+\left(2+8\right)+\left(3+7\right)+\left(4+6\right)+5\)
\(=10+10+10+10+5\)
\(=10.4+5\)
\(=40+5\)
\(=45\)
2 + 4 + 7 + 7
= 6 + 7 + 7
= 13+ 7
= 20
20
20
20
20
hừ khó nhỉ
20
2+4+7+7
= 6 + 14
= 20