5-2x (x-1)(x+1) (x+2)(1-3x) _____ + ___________=___________ 3 3x-1 9x-3 21/09/2021 Bởi Amara 5-2x (x-1)(x+1) (x+2)(1-3x) _____ + ___________=___________ 3 3x-1 9x-3
Đáp án: `(5-2x)/3+((x-1)(x+1))/(3x-1)=((x+2)(1-3x))/(9x-3)` (đk: `x\ne1/3`) `<=>(5-2x)/3+(x^2-1)/(3x-1)=((x+2)(1-3x))/(3(3x-1))` `<=>((5-2x).(3x-1)+3.(x^2-1))/(3(3x-1))=((x+2)(1-3x))/(3(3x-1))` `=>(5-2x)(3x-1)+3(x^2-1)=(x+2)(1-3x)` `<=>-6x^2+17x-5+3x^2-3=-3x^2-5x+2` `<=>-3x^2+17x-8=-3x^2-5x+2` `<=>-3x^2+3x^2+17x+5x=2+8` `<=>22x=10` `<=>x=5/11(\text{tmđk})` Vậy `S={5/11}` Bình luận
Đáp án:
`(5-2x)/3+((x-1)(x+1))/(3x-1)=((x+2)(1-3x))/(9x-3)` (đk: `x\ne1/3`)
`<=>(5-2x)/3+(x^2-1)/(3x-1)=((x+2)(1-3x))/(3(3x-1))`
`<=>((5-2x).(3x-1)+3.(x^2-1))/(3(3x-1))=((x+2)(1-3x))/(3(3x-1))`
`=>(5-2x)(3x-1)+3(x^2-1)=(x+2)(1-3x)`
`<=>-6x^2+17x-5+3x^2-3=-3x^2-5x+2`
`<=>-3x^2+17x-8=-3x^2-5x+2`
`<=>-3x^2+3x^2+17x+5x=2+8`
`<=>22x=10`
`<=>x=5/11(\text{tmđk})`
Vậy `S={5/11}`