1000=1000

10000=10000

80=80

số la mã cơ

a, 21 + 8 = 29

   6 + 72 = 78

b) 42 + 20 = 62

    80 + 15 = 95

c, 630 + 50 = 680

    10 + 470 = 480

kik mik mik k lại

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~~~~~

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50 x 100 - 80 + 70 + 5 + 5

= 5000 - 80 + 70 + 5 + 5

= 4920 + 70 + 5 + 5

= 4990 + 5 + 5

= 4995 + 5

= 5000

< mình k bn r` mà sao bn không k mình, đồ gian >

10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90

= ( 10 + 90 ) + ( 20 + 80 ) + ( 30 + 70 ) + ( 40 + 60 ) + 50

= 100 + 100 + 100 + 100 + 50

= 100 x 4 + 50

= 400 + 50

= 450

Học tốt #

Ai nhanh mình k 3 k

64:x=4 

=> x=64:4=16 

64:x=64:16=4 

80:x=80:16=5 

2/ 45

47

47

47

96

96

96

\(80-\left(x-23\right)=56\)

               \(x-23=80-56\)

                \(x-23=24\)

                          \(x=24+23\)

                           \(x=47\)

\(67-\left(x-30\right)=1\)

                \(x-30=67-1\)

                 \(x-30=66\)

                          \(x=66+30\)

                           \(x=96\)

1 + 2 + 3 + 5 + 8= 19

321 + 654 + 894 = 1869

nhớ ủng hộ mik nghen

1 + 2 + 3 + 5 + 8 = 19.

321 + 654 + 894 = 1869.

C1: \(\left(\frac{3}{5}+\frac{4}{9}\right)\cdot\frac{3}{8}=\frac{47}{45}\cdot\frac{3}{8}=\frac{141}{360}=\frac{47}{120}\)

C2: \(\left(\frac{3}{5}+\frac{4}{9}\right)\cdot\frac{3}{8}=\frac{3}{5}\cdot\frac{3}{8}+\frac{4}{9}\cdot\frac{3}{8}=\frac{9}{40}+\frac{12}{72}=\frac{47}{120}\)

C1: ( \(\frac{3}{5}+\frac{4}{9}\) ) * \(\frac{3}{8}\) 

= \(\frac{47}{45}\) * \(\frac{3}{8}\) = \(\frac{47}{120}\) 

C2: Đề

= 3/5 * 3/8 + 4/9 * 3/8

= 9/40 + 1/6

= 47/120

4+8+7+9+5+2+1+3*0=36

4 + 8+7+9+5+2 +1 +0

B1

a) 17 b) 6 c) 112 d)9687

B2

100-x=33

x=100-33

x= 67

Ko bít

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