Hoàng Phương Thảo

Cho phân số \(\frac{37}{99}\), cộng tử với STN n, lấy mẫu trừ đi n, ta được một phân số mới bằng \(\frac{3}{5}\). Tìm số n

Bò Vinamilk 3 không (Hộ...
22 tháng 8 2019 lúc 10:46

Ta có thể viết: \(\frac{37+n}{99-n}=\frac{3}{5}\)

Mặc dù vậy nhưng tổng của tử và mẫu k đổi

Tổng ban đầu là:

37 + 99 = 136

Như vậy 136 tương ứng với 3 + 5 = 8 phần ở phân số mới

Tử mới là:

136 : 8 x 3 = 51

Như vậy n = 51 - 37 = 14

Hội con 🐄 chúc bạn học tốt!!! 

n=14 

hok tot

hi

🎉 Party Popper
22 tháng 8 2019 lúc 10:59

Ta có: \(\frac{37+n}{99-n}=\frac{3}{5}\)

<=> 5(37 + n) = 3(99 - n)

<=> 185 + 5n = 297 - 3n

<=> 8n = 112

<=> n = 14

Lily
22 tháng 8 2019 lúc 10:59

                                                              Bài giải

                    Ta có : Tổng tủ số và mẫu số của phân số ban đầu là :

                                               37 + 99 = 136

       Vì người ta lấy cùng môt số tự nhiên n thêm vào tử số, bớt đi ở mẫu số nên tổng của tử số và mẫu số lúc sau không đổi

                                   Tử số lúc sau khi thêm n là:

                                              136 : ( 3 + 5 ) x 3 =  51

                                   Số tự nhiên n là : 

                                                  51 - 37 = 14

                                                   Đáp số : 14

Fudo
22 tháng 8 2019 lúc 11:07

                                                            Bài giải

Ta có : \(\frac{37+n}{99-n}=\frac{3}{5}\)

\(3\left(99-n\right)=5\left(37+n\right)\)

\(297-3n=185+5n\)

\(5n+3n=297-185\)

\(8n=112\)

\(n=112\text{ : }8\)

\(n=14\)

ミ★Zero ❄ ( Hoàng Nhật )
17 tháng 4 2020 lúc 19:22

14 nha bạn

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pham doanh thai
17 tháng 4 2020 lúc 19:39

14 dung 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000% nha ban

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