Question

Cho a,b ϵ Z, b>0. So sánh a/b và a+2/b+2

Answer 1

Đề thiếu

Answer 2

Ta có: a(b +2001) = ab + 2001a

            b(a +2001)=ab + 2001b

vì b >0 nên b + 2001 > 0

Answer 3

Ta có: a(b +2001) = ab + 2001a

            b(a +2001)=ab + 2001b

vì b >0 nên b + 2001 > 0

a) Nếu a > b thì ab + 2001a > ab + 2001b

 

Quảng cáo

 

⇒a(b+2001)>b(a+2001)⇒ab>a+2001b+2001⇒a(b+2001)>b(a+2001)⇒ab>a+2001b+2001

b) Nếu a < b thì ab + 2001a < ab + 2001b               

⇒a(b+2001)<b(a+2001)⇒ab<a+2001b+2001⇒a(b+2001)<b(a+2001)⇒ab<a+2001b+2001

c) Nếu a = b thì ab=a+2001/b+2001

Answer 4

mẫu

nha bạn!