2+2³+2⁵+2⁷+...+2¹⁹⁹⁹

(2+2³)+(2⁵+2⁷)+...+(2¹⁹⁹⁷+2¹⁹⁹⁹)

(2)x(1+2²)+(2⁵)x(1+2²)+...+(2¹⁹⁹⁷)x(1+2²)

(1+2²)x(2+2⁵+...+2¹⁹⁹⁷⁾

5x(2x(1+2⁴+...+2¹⁹⁹⁶)

10x(1+2⁴+...+2¹⁹⁹⁶)(dpcm)

thấy đúng thì k nha

đổi : 1 phút 25 giây = 1,25 giây

quãng đường tàu hỏa đi được trong 1,25 phút là : \(800\times1,25=1000\left(m\right)\)

khi toa cuối ra khỏi hầm thì đấu toa đã cách hầm 85 m .Vậy đường hầm dài là: \(1000-85=915\left(m\right)\)

hai câu này sai hết

1. English hasn't learned for a long time.

2.A lot of food are being cooked for the party by my sister

3.My clothes was being washed whwn you call.

4.Coffee is being drunk in the living room by Mr Nam now.

5.Were those book bought at Phu Tho bookstore.

6.English is spoken everywhere.

7.A lot of English songs can be sung very well by my brother.

8.The room is being decorated by my friend.

9.That film has been seen four times by Lan.

10.I am taught English by my father everyday.

chúc làm bài tốt!