\(\frac{3}{6-2x}=\frac{-3}{2\left(x-3\right)}=\frac{-3\cdot3}{2\left(x-3\right)\cdot3}=\frac{-9}{6\left(x-3\right)}\)

\(\frac{2}{x-3}=\frac{2\cdot6}{6\left(x-3\right)}=\frac{12}{6\left(x-3\right)}\)

\(\frac{-5}{3x-9}=\frac{-5}{3\left(x-3\right)}=\frac{-5\cdot2}{3\left(x-3\right)\cdot2}=\frac{-10}{6\left(x-3\right)}\)

\(\frac{7}{4-2x}=\frac{-7}{2\left(x-2\right)}=\frac{-7\cdot\left(x-2\right)}{2\left(x-2\right)\left(x-2\right)}=\frac{-7x+14}{2\left(x-2\right)^2}\)

\(\frac{2}{x^2-4x+4}=\frac{2}{\left(x-2\right)^2}=\frac{2\cdot2}{\left(x-2\right)^2\cdot2}=\frac{4}{2\left(x-2\right)^2}\)

MTC: 42 x 2 y 5 ;   nhân tử phụ 1: 3 y 4 ;   nhân tử phụ 2: 2x

Quy đồng 

Mẫu thức chung: 42 x 2 y 5

Ta có

Mẫu thức chung: 102 x 4 y 3

Ta có

MTC: 102 x 4 y 3 ;   NTP 1: y 2 ,   NTP2: 3 x 3

Quy đồng 

M T C : 120 x 4 y 5 ;     N T P 1 : 12 y 4 ;     N T P 2 : 15 x 2 y 3 ;     N T P 3 : 40 x 3

Quy đồng:

M T C : 18 x 3 y 4     N T P 1 : 3 y 2 ;     N T P 2 : 2 x

Quy đồng:

MTC: 5x(x – 2y);  

NTP 1: x – 2y;  

NTP2: 5x

Quy đồng: