a) \(\frac{14}{5}\div x=\frac{13}{5}-\frac{7}{5}\)

\(\frac{14}{5}\div x=\frac{6}{5}\)

\(x=\frac{14}{5}\div\frac{6}{5}\)

\(x=\frac{7}{3}\)

b) \(\frac{1}{3}\cdot x+\frac{5}{6}\cdot x=\frac{12}{5}\)

\(\left(\frac{1}{3}+\frac{5}{6}\right)\cdot x=\frac{12}{5}\)

\(\frac{7}{6}\cdot x=\frac{12}{5}\)

\(x=\frac{12}{5}\div\frac{7}{6}\)

\(x=\frac{72}{35}\)

\(\frac{14}{5}\) :  X = \(\frac{13}{5}\) -  \(\frac{7}{5}\)

\(\frac{14}{5}\): X   =       \(\frac{6}{5}\)

       X         =        \(\frac{14}{5}\) : \(\frac{6}{5}\) ( Tìm số chia)

       X         =              \(\frac{7}{3}\)

\(\frac{1}{3}\) x  X  + \(\frac{5}{6}\) x  X = \(\frac{12}{5}\)

( \(\frac{1}{3}\) + \(\frac{5}{6}\))  x  X = \(\frac{12}{5}\)

      \(\frac{7}{6}\)           x  X  = \(\frac{12}{5}\)

             X                  =  \(\frac{12}{5}\) : \(\frac{7}{6}\) ( Tìm thừa số)

             X                  =          \(\frac{72}{35}\)

14/5 : x = 13/5 - 7/5

14/5 : x = 6/5

         x = 14/5 : 6/5

         x = 14/5 x 5/6

         x = 7/3

b)

1/3 * x + 5/6 * x = 12/5

x * ( 1/3 + 5/6)   = 12/5

x * 2/6 + 5/6      = 12/5

x * 7/6              = 12/5

x                      = 12/5 : 7/6

x                      = 72/35 

:( 

2/3×3/4×4/5÷1/5=2

2/5×3/4×5/6÷3/4=0.33333333333......

2/3 x 3/4 x 4/5 : 1/5 = 6/12 x 4/5 :1/5 = 24/60 :1/5 = 4/10 : 1/5 = 4/10 x 5/1 = 20/10 = 2

2/5 x 3/4 x 5/6 : 3/4 = 6/20 x 5/6 : 3/4 = 3/10 x 5/6  : 3/4 = 15/60 : 3/4 = 1/4 : 3/4 = 1/4 x 4/3 = 4/12 = 1/3

k cho mk nha!

\(\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}\div\frac{1}{5}\)

\(=\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}\times\frac{5}{1}\)

\(=\frac{2\times3\times4\times5}{3\times4\times5\times1}\)

\(=\frac{2}{1}\)

\(=2\)

\(\frac{2}{3}\times\frac{1}{5}+\frac{3}{10}\times\frac{2}{3}+\frac{4}{6}\times\frac{1}{2}\)

\(=\frac{2}{3}\times\frac{1}{5}+\frac{3}{10}\times\frac{2}{3}+\frac{2}{3}\times\frac{1}{2}\)

\(=\frac{2}{3}\times\left(\frac{1}{5}+\frac{3}{10}+\frac{1}{2}\right)\)

\(=\frac{2}{3}\times\frac{10}{10}\)

\(=\frac{2}{3}\)

a/  x² + (y - 3)² = 5 . Phai hieu bai toan yeu cau phan h so 5 thanh tong cua hai so chinh phuong. Chi co mot cach duy nhat 5 = 1 + 4  Nhu vay \(x^2+\left(y-3\right)^2=5\Leftrightarrow\orbr{\begin{cases}x^2=1;\left(y-3\right)^2=4\\x^2=4;\left(y-3\right)^2=1\end{cases}}.\)  cac ban giai tiep nhe.Co kho gi nua dau.                                             b/     3(x-1)² + y² = 6 . Phai hiai toan yeu cau ta s 6 thanh tong hai sduong, trong do co mot so chia het cho 3. Co cac truong hop sau:      - T/h 1: 3(x-1)² = 0  Loai vi khi do y² = 6, khong co gia tr nguyen y nao.                                                                                                                  - T/h 2: 3(x-1)² = 3 thi kh do y² = 3, khong co gia tri nguyen nao cua y thoa man. T/h nay cung loai.                                                                -  T/h 3:   3(x-1)² = 6 tuc la (x-1)² = 2, khong co gia tri nguyen nao cua x thoa man, T/h nay cung bi loai.                                                    Nhu vay: Khong co cap so nguyen (a, y) nao thoa man yeu cau bai ra.

T5Tt%$

3 x \(\frac{4}{11}\) = \(\frac{3}{1}\) x \(\frac{4}{11}\) = \(\frac{12}{11}\)

1 : \(\frac{5}{4}\) = \(\frac{1\times4}{5}\) = \(\frac{4}{5}\)

\(\frac{4}{5}\) x \(\frac{6}{7}\) + \(\frac{2}{3}\) = \(\frac{24}{35}\) + \(\frac{2}{3}\) = \(\frac{142}{105}\)

\(\frac{3}{4}\) + \(\frac{1}{2}\) : \(\frac{5}{6}\) = \(\frac{3}{4}\) + \(\frac{1}{2}\) x \(\frac{6}{5}\) = \(\frac{3}{4}\)+ \(\frac{6}{10}\) \(\frac{27}{20}\)

\(\frac{3}{4}\)+ \(\frac{1}{2}\) = \(\frac{3}{4}\) + \(\frac{2}{4}\)= \(\frac{5}{4}\)