\(a,2\times3=6\)

\(6\times2=12\)

\(10\times2=20\)

\(1\times2=2\)

\(b,5\times7=35\)

\(9\times5=45\)

\(5\times8=40\)

\(1\times5=5\)

Chiều rộng hình chũ nhật là :

50 x \(\frac{1}{5}\)= 10 ( m )

Chu vi hình chữ nhật là ;

( 50 + 10 ) x 2 = 120 ( m )

Đáp số : 120 m

chiều rộng hình chữ nhật là:

50: 5 = 10 (m)

chu vi hình chữ nhật là:

(50+ 10) x 2= 120 (m)

10+9-8+7-6+5-4+3-2+1-0

= 10 +[(9 - 8) + (7 - 6) + (5 - 4) + (3 - 2) + (1 - 0)]

= 10 + [1 + 1 + 1 + 1 + 1]

= 10 + 1 x 5

= 10 + 5

= 15

15

Số số hạng của dãy số là:

10-0+1=11(số)

Tổng của dãy số là: \(\left(10+0\right)\times\frac{11}{2}=10\times\frac{11}{2}=5\times11=55\)

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còn 200 kg

5 bao nặng số ki lô gam là :

50 x 5 = 250 ( kg )

Mẹ đã lấy số ngô là :

250 x 1/5 = 50 ( kg )

Trong kho còn lại số ki lô gam ngô là :

250 - 50 = 200 ( kg )

Đáp số : 200 kg

Bảng nhân `2`

` 2xx1 = 2`

` 2xx2 = 4`

` 2xx3 = 6`

` 2xx4=8`

` 2xx5 = 10 `

` 2xx6=12`

` 2 xx 7= 14`

` 2xx 8 = 16`

` 2 xx9 = 18`

` 2 xx 10 = 20`

Bảng nhân `5`

` 5 xx1 = 5`

` 5xx2=10`

` 5xx 3= 15`

` 5 xx4=20`

` 5xx5=25`

` 5xx6 = 30`

` 5xx7 = 35`

` 5xx 8 = 40`

` 5xx9 = 45`

` 5 xx10 = 50`

- Bảng nhân 2:

2 × 1 = 2                          2 × 6 = 12

2 × 2 = 4                          2 × 7 = 14

2 × 3 = 6                          2 × 8 = 16 

2 × 4 = 8                          2 × 9 = 18

2 × 5 = 10                        2 × 10 = 20

- Bảng nhân 5:

5 × 1 = 5                          5 × 6 = 30

5 × 2 = 10                        5 × 7 = 35

5 ×  3 = 15                       5 × 8 = 40

5 × 4 = 20                        5 × 9 = 45

5 × 5 = 25                        5 × 10 = 50

Chiều rộng là : 

50 - 15 = 35 ( m ) 

Chu vi hình chữ nhật là :                            

( 35 + 50) x2 = 170 ( m )

Đáp số : 170 m

      GIẢI :

Chiều rộng của hình chữ nhật là :

   50 - 15 = 35 ( cm )

Chu vi hình chữ nhật là :

  ( 50 + 35 ) x 2 = 170 ( cm )

      Đáp số : 170 cm

bạn ơi không phải 15 nha mà là 1/5 nha bạn mình viết nhầm

goi so can tim la a: a:3 du 2;a:5du4;a:7 du 6   nen a+1 chia het cho 3,5,7

                                                                   hay a+1chia het cho3x5x7=105                                                                                                                                                     ma a nho nhat nen a+1=105=>a=104                                                 

                                                                 vay a=104

 Ta nhận thấy số dư của các phép chia là số dư lớn nhất. Vậy số cần tìm chính là số nhỏ nhất chia hết cho 3, chia hết cho 5 và chia hết cho 7 bớt đi 1 đơn vị.
         Số cần tìm là:   3 x 5 x 7 – 1 =104
         Đáp số:         104

x-5=0

x=0+5

x=5

x*7=14

x=14:7

x=2

x+2=6

x=6-2

x=4                            

a) x - 5 = 0

=> x     = 0 + 5

=> x      = 5

b) x . 7 = 14 

=> x     = 14 : 7

=> x      = 2

c) x + 2 = 6

=> x      = 6-2

=> x       = 4

Ai k mik mik k lại