Dear Mary,

It's great to know that you're coming to Viet Nam. I hope you’ll have a good time spending one day in Ha Noi.

There are many interesting places in the city, but I think within one day you are able to visit three places. The first place I suggest is Viet Nam National Museum of History. Since you like history very much, it's a must-see place. There's an extensive collection of artefacts tracing ret Sam's history. They're arranged chronologically from primitive to modem times. The second place is Hoan Kiem Lake. It's one of the symbols of Ha Noi. There you can enjoy the beautiful scenery and visit Ngoc Son Temple. You can also go for a walk at the Old Quarter, wander around the old streets and some ancient houses to explore Vietnamese culture. Fortunately, these places are close to one another, so you can walk around easily.

Tell me when you're coming, so I can show you around these places.

Look forward to seeing you soon!

Best wishes,

Hong Anh

hok tốt nha bạn

goị a là tử , b là mẫu

theo đề bài ta có: \(\frac{a}{b}\)(a,b là số tự nhiên) a+b=2015 => a=2015-b, a là tử số nên a nhỏ nhất là 0 và lớn nhất là 2014, b nhỏ nhất là 1 và lớn nhất là 2015

vậy có 2015 cách chọn a, 2015 cách chọn b

=> có 2015x2015=400225 cách chọn phân số                            

32+(x+3)=17 

        x+3=32-17

        x+3=15

            x=15-3

            x=12

32+2(x-2)=64

      2(x-2)=64-32

      2(x-2)=32

         x-2=32:2

         x-2=16

            x=16+2

             x=18

a) 32+(x+3)=17

=>x+3=17-32=-15

=>x=-15-3=-18

b) 32+2(x-2)=64

=>2(x-2)=64-32=32

=>x-2=32:2=16

=>x=16+2=18

=>x=18