`cccolor{#8FBC8F}{~} cccolor{#C1FFC1}{b} cccolor{#B4EEB4}{u} cccolor{#9BCD9B}{i} cccolor{#698B69}{g} cccolor{#2E8B57}{i} cccolor{#54FF9F}{a} cccolor{#4EEE94}{p} cccolor{#43CD80}{h} cccolor{#98FB98}{o} cccolor{#008B45}{n} cccolor{#00FF00}{g} cccolor{#00EE00}{9} cccolor{#00CD00}{9} cccolor{#ADFF2F}{9} cccolor{#228B22}{~}`

Bài `1:`

`a) (5x+10)/(25x+50) ( x ne -2)`

`= (5(x+2))/(25(x+2))`

`= 5/25=1/5`

`b) (x^2-3x+1)/(2x^2) - (5x-1-x^2)/(2x^2) (xne0)`

`= (x^2-3x+1-(5x-1-x^2))/(2x^2)`

`= (x^2-3x+1-5x+1+x^2)/(2x^2)`

`= (2x^2-8x+2)/(2x^2)`

`= (2(x^2-2x+1))/(2x^2)`

`= (x-1)^2/x^2`

`= ((x-1)/x)^2`

`c) (2x+10)/(x-3)^2 : (x+5)^3/(x^2-9) (x ne 3; x ne -3)`

`= (2(x+5))/(x-3)^2 . (x^2-9)/(x+5)^2`

`= (2(x+5))/(x-3)^2 . ((x-3)(x+3))/(x+5)^2`

`= 2/((x+3)(x+5))`

Bài `2:`

`P=(x^2-y^2)/((x+y)(ay-ax))`

`P=((x-y)(x+y))/(-a(x+y)(x-y))`

`P=-a`

`=> P=-a` không phụ thuộc vào `x,y.`

$\color{#29B6F6}{\heartsuit Phuongg \ Li nhh \heartsuit}$