Thoi gian ban ngay cua mua ha dai hon ban dem

Thoi gian ban dem cua mua dong dai hon ban ngay

Ten cac cay: san , trau khong , ho tieu , cay but moc , cay to hong

- Nhom a: san

- Nhom b: trau khong , ho tieu

- Nhom c: cay but moc

- Nhom d: cay to hong

Dac diem phan loai:

- Re cu: re phinh to

- Re moc: re phu moc tu than va canh tren mat dat , moc vao tru bam

- Re tho: re moc nguoc len tren mat dat

- Re giac mut: bien doi thanh giac mut dam vao than va canh cua cay khac

Phai thu hoach cac cay co re cu truoc khi ra hoa vi neu khong , chat dinh duong cua cu lai chuyen sang nuoi hoa , cu se khong con chat dinh duong

Nhung diem giong nhau giua than va canh: mang la , hoa

Vi tri choi ngon: nam dau than va canh

Choi ngon se phat trien thanh than chinh

   (-17) + 17 + 5 + 8 + (-3)

= (17 - 17) + (5 + 8) - 3

= 0 + 13 - 3

= 10

Giong: tren mat dat

Khac:

Re tho: re moc nguoc len tren mat dat

Re giac mut: bien doi thanh giac mut dam vao than va canh cua cay khac

Cau tao ngoai: hinh tru

+ Phan duoi: de \(\rightarrow\) bam

+ Phan tren: lo mieng va cac tua mieng

Co the doi xung toa tron

Giong nhau : Co mam la

Khac nhau :

Choi la :

+ Co mo phan sinh ngon

+ Phat trien canh mang la

Choi hoa :

+ Co mam hoa

+ Phat trien canh mang hoa hoac hoa

Câu A nha bn

A = 2A - A = ( 2 + 2² + 2³ + 2⁴ + ... + 2²⁰¹⁸ ) - ( 1 + 2 + ... + 2²⁰¹⁷ )

= 2²⁰¹⁸ - 1

Vì 2²⁰¹⁸ - 1 < 2²⁰¹⁸ nên A < B.