Đáp án:
Giải thích các bước giải:
a) A=1.2−12!+2.3−13!+3.4−14!+...+99.100−1100!A=1.2−12!+2.3−13!+3.4−14!+...+99.100−1100!
A=1.22!−12!+2.33!−13!+3.44!−14!+...+99.100100!−1100!A=1.22!−12!+2.33!−13!+3.44!−14!+...+99.100100!−1100!
A=1−12!+11!−13!+12!−14!+...+198!−1100!A=1−12!+11!−13!+12!−14!+...+198!−1100!
A=1+1−1100!A=1+1−1100!
A=2−1100!<2A=2−1100!<2
B=2019.4036+40182019.2019−10B=2019.4036+40182019.2019−10
B=2019.4036+4018+102019.2019−10+10B=2019.4036+4018+102019.2019−10+10
B=2019.4036+40282019.2019B=2019.4036+40282019.2019
B>2019.4036+40382019.2019B>2019.4036+40382019.2019
B>2019.4036+2019.22019.2019B>2019.4036+2019.22019.2019
B>2019.(4036+2)2019.2019B>2019.(4036+2)2019.2019
B>2019.40382019.2019=40382019=2B>2019.40382019.2019=40382019=2
Ta có: A<2;2<BA<2;2<B
⇒A<B
day nha ban cho mk 5 sao