\(=90\left(11+31+2\cdot29\right)=90\cdot100=9000\)

a)

5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45

=90.11+90.31+2.29.90=90.11+90.31+2.29.90

=90.(11+31+2.29)=90.(11+31+2.29)

=90.100=9000

b)

37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55

=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11

=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44

=39.65+65.(17+44)=39.65+65.(17+44)

=39.65+65.61=39.65+65.61

=65.(39+61)=65.(39+61)

=65.100=6500

a.(5.18).11+(9.10).31+2.2.29.45

=90.11+90.31+(2.45).2.29

=90.11+90.31+90.2.29

=90.(11+31+2.29)

=90.100

=9000

a)

5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45

=90.11+90.31+2.29.90=90.11+90.31+2.29.90

=90.(11+31+2.29)=90.(11+31+2.29)

=90.100=9000

b)

37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55

=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11

=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44

=39.65+65.(17+44)=39.65+65.(17+44)

=39.65+65.61=39.65+65.61

=65.(39+61)=65.(39+61)

=65.100=6500

a) \(39\times118+29\times82\)

\(=39\times2\times59+29\times2\times41\)

\(=2\times\left(39\times59+29\times41\right)\)

\(=2\times\left(2301+1189\right)\)

\(=2\times3490\)

\(=6980\)

b) \(37\times39+78\times14-13\times85-52\times55\)

\(=37\times3\times13+6\times13\times14+13\times85-4\times13\times55\)

\(=13\times\left(37\times3+6\times14+85-4\times55\right)\)

\(=13\times\left(111+84+85-220\right)\)

\(=13\times\left(280-220\right)\)

\(=13\times60\)

\(=780\)

c) \(368:16+752:16+480:16\)

\(=\left(368+752+480\right):16\)

\(=\left(1120+480\right):16\)

\(=1600:16\)

\(=100\)

d) \(5\times11\times18+9\times31\times10+4\times29\times45\)

\(=5\times11\times9\times2+9\times31\times10+2\times2\times29\times5\times9\)

\(=10\times9\times11+10\times9\times31+10\times29\times2\times9\)

\(=90\times11+90\times31+90\times29\times2\)

\(=90\times\left(11+31+29\times2\right)\)

\(=90\times\left(42+58\right)\)

\(=90\times100\)

\(=9000\)

1)  \(35.18-5.7.28=35.18-35.28=35\left(18-28\right)=-350\)

2)  \(45-5\left(12+9\right)=45-60-45=-60\)

3)  \(24\left(16-5\right)-16\left(24-5\right)=24.16-24.5-16.24+16.5=5\left(16-24\right)=5.8=40\)

4)  \(29\left(19-13\right)-19\left(29-13\right)=29.19-29.13-19.29+19.13=13\left(19-29\right)=-130\)

5)  \(31.\left(-18\right)+31.\left(-81\right)-31=-31.\left(18+81+1\right)=-3100\)

6)  \(\left(-12\right).47+\left(-12\right).52+\left(-12\right)=\left(-12\right)\left(47+52+1\right)=-1200\)

7)  \(13\left(23+22\right)-3\left(17+28\right)=13.45-3.45=45.\left(13-3\right)=450\)

8)  \(-48+48.\left(-78\right)+48.\left(-21\right)=-48\left(1+78+21\right)=-4800\)

a)\(\frac{-5}{18}+\frac{32}{45}-\frac{9}{10}\)

\(=\frac{-25}{90}+\frac{64}{90}-\frac{81}{90}\)

\(=-\frac{42}{90}=-\frac{7}{15}\)

b)\(\frac{3}{4}-\left(-\frac{5}{8}\right)+\frac{9}{4}-\frac{3}{16}\)

\(=\frac{3}{4}+\frac{5}{8}+\frac{9}{4}-\frac{3}{16}\)

\(=\frac{12}{16}+\frac{10}{16}+\frac{36}{16}-\frac{3}{16}\)

\(=\frac{58}{16}=\frac{29}{8}\)

c) \(\frac{11}{125}-\frac{17}{18}-\frac{5}{7}+\frac{4}{9}+\frac{17}{14}=\frac{11}{125}\)

d) \(\frac{-2}{5}-\frac{3}{10}-\left(-\frac{1}{2}\right)\)

\(=-\frac{2}{5}-\frac{3}{10}+\frac{1}{2}\)

\(=-\frac{4}{10}-\frac{3}{10}+\frac{5}{10}\)

\(=-\frac{2}{10}=-\frac{1}{5}\)

Em nến gõ bằng công thức toán học em nhé. Như vậy mọi người nới hiểu đúng đề bài để trợ giúp cho em một cách tốt nhất em ạ!

chócfghv

1) 35.18 - 5.7.28

= 35.18 - 35.28

= 35.(18 - 28)

= 35.(-10)

= -350

2) 45 - 5.(12 + 9)

= 45 - 5.12 - 5.9

= 45 - 60 - 45

= (45 - 45) - 60

= 0 - 60

= -60

3) 24.(16 - 5) - 16.(24 - 5)

= 24.16 - 24.5 - 16.24 + 16.5

= (24.16 - 16.24) - (24.5 + 16.5)

= 0 - (24.5 + 16.5)

= -24.5 + 16.5

= 5.(-24 + 16)

= 5.(-8)

= -40

4) 29.(19 - 13) - 19.(29 - 13)

= 29.19 - 29.13 - 19.29 + 19.13

= (29.19 - 19.29) + (19.13 - 29.13)

= 0 + (19.13 - 29.13)

= 19.13 - 29.13

= 13.(19 - 29)

= 13.(-10)

= -130

5) 31.(-18) + 31.(-81) - 31

= 31.(-18 - 81 - 1)

= 31.(-100)

= -3100

6) (-12).47 + (-12).52 + (-12)

= (-12).(47 + 52 + 1)

= (-12).100

= -1200

7) 13.(23 + 22) - 3.(17 + 28)

= 13.45 - 3.45

= 45.(13 - 3)

= 45.10

= 450

8) -48 + 48.(-78) + 48.(-21)

= 48.(-1) + 48.(-78) + 48.(-21)

= 48.(-1 - 78 - 21)

= 48.(-100)

= -4800

Cố gắng lên nhé em Hoàng Mai Hoa

1)35.18-5.7.28

= 35 . 18 - 35 . 28

= 35 . ( 18 - 28 )

= 35 . ( - 10 )

= - 350

1) 35.18 - 5.7.28

= 35.18 - 35.28

= 35.(18 - 28)

= 35.(-10)

= -350

2) 45 - 5.(12 + 9)

= 45 - 5.12 - 5.9

= 45 - 60 - 45

= (45 - 45) - 60

= 0 - 60

= -60

3) 24.(16 - 5) - 16.(24 - 5)

= 24.16 - 24.5 - 16.24 + 16.5

= (24.16 - 16.24) - (24.5 + 16.5)

= 0 - (24.5 + 16.5)

= -24.5 + 16.5

= 5.(-24 + 16)

= 5.(-8)

= -40

4) 29.(19 - 13) - 19.(29 - 13)

= 29.19 - 29.13 - 19.29 + 19.13

= (29.19 - 19.29) + (19.13 - 29.13)

= 0 + (19.13 - 29.13)

= 19.13 - 29.13

= 13.(19 - 29)

= 13.(-10)

= -130

5) 31.(-18) + 31.(-81) - 31

= 31.(-18 - 81 - 1)

= 31.(-100)

= -3100

6) (-12).47 + (-12).52 + (-12)

= (-12).(47 + 52 + 1)

= (-12).100

= -1200

7) 13.(23 + 22) - 3.(17 + 28)

= 13.45 - 3.45

= 45.(13 - 3)

= 45.10

= 450

8) -48 + 48.(-78) + 48.(-21)

= 48.(-1) + 48.(-78) + 48.(-21)

= 48.(-1 - 78 - 21)

= 48.(-100)

= -4800

Cố gắng lên nhé ạ