Đáp án:
`↓↓`
Giải thích các bước giải:
`a) (5x+10)/(4x-8) . (4-2x)/(x+2)`
`=(5(x+2))/(4(x-2)). (2(2-x))/(x+2)`
`=(-5)/2`
`b) (4x+8)/(x-10)^3 . (2x-20)/(x+2)^2`
`=(4(x+2))/(x-10)^3 . (2(x-10))/(x+2)^2`
`=8/((x-10)^2. (x+2))`
`c) (2x^2-20x+50)/(3x+3) . (x^2-1)/(4(x-5)^3)`
`=(2(x^2-10x+25))/(3(x+1)) . ((x-1)(x+1))/(4(x-5)^3)`
`=(2.(x-5)^2)/(3(x+1)) . ((x-1)(x+1))/(4(x-5)^3)`
`=(2.(x-1))/(12.(x-5))`
`=(2x-2)/(12x-60)`
`d) (x+3)/(x^2-4) . (8-12x+6x^2-x^3)/(9x+27)`
`=(x+3)/((x-2)(x+2)) . (2-x)^3/(9(x+3))`
`=(-(x-2)^2)/(9(x+2))`
