1+2+3+4+5+6+7+8+9=45

1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9

= ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5

= 10 + 10 + 10 + 10 + 5

= 20 + 10 + 10 + 5

= 30 + 10 + 5 

= 40 + 5 

= 45

( 1+9 ) +( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 5

10+10+10+10+5

45
 

1-1/2+1/2-1/3+1/3-1/4+1/4-1/5

=(1-1/5)+(1/2-1/2)+(1/3-1/3)+(1/4-1/4)

=(5/5-1/5)+0+0+0=4/5

Tại bấm máy tính mà ra

Bấm kiểu j jợ

LA 539

a)49.7.7³

=7².7¹.7³

=7⁶

b)9⁸:3²

9⁸=(3²)⁸

=3¹⁶:3²

=3¹⁴

Chúc em học tốt^^

câu 2  còn câu 1 em ghi rõ đề ra chị không hiểu

 Gọi số cần tìm là X

   Ta có : X :5 + 24 = 33

              X : 5       =  33 - 24

              X : 5       =     9

              X            = 9 * 5

              X            45

1*1=1

2*2=4 3*3=9 4*4=16 bạn nhé

1*1=1

2*2=4

3*3=9

4*4=16

1 * 1 = 2

2 * 2 = 16 

3 * 3 = 54

4 * 4 = 128

Đúng thì k nha

7 nka ban

8+2-3=8+2=10-3=7

8 + 2 - 3

= 10 - 3

= 7

k cái nha

                                         My best friend name's Như.

                             She has long black hair and big eyes.

                             She is light.She play badminton with me.

                             She swimming.And she eat noodles

                             and drink orange juice.

                             I love my best friend

My best friend in high school is Lan. Lan sits next to me in class, eats with me at break time, and hangs out with me after school. She has long and beautiful hair; my mother always says that I need to pay more attention to my hair so it can be pretty as hers. I am good at English while Lan is excellent in Math, therefore we can help each other every time one of us has trouble in understanding those subjects. Besides our study, Lan is always by my side whenever I feel upset. I tell her everything, and only her can know my true feelings. We have been best friends since our young age, and I will keep this friendship forever.

Tham khảo nha!

My best friend in high school is Lan. Lan sits next to me in class, eats with me at break time, and hangs out with me after school. She has long and beautiful hair; my mother always says that I need to pay more attention to my hair so it can be pretty as hers. I am good at English while Lan is excellent in Math, therefore we can help each other every time one of us has trouble in understanding those subjects. Besides our study, Lan is always by my side whenever I feel upset. I tell her everything, and only her can know my true feelings. We have been best friends since our young age, and I will keep this friendship forever.

Hc tốt #