Toán tìm x biết x+1/19 + x+3/17 + x+6/14 = -3 06/09/2021 By Serenity tìm x biết x+1/19 + x+3/17 + x+6/14 = -3
*Lời giải : `(x + 1)/19 + (x + 3)/17 + (x + 6)/14 = -3` `⇔ (x + 1)/19 + (x + 3)/17 + (x + 6)/14 + 3 = 0` `⇔ ( (x + 1)/19 + 1) + ( (x + 3)/17 + 1) + ( (x + 6)/14 + 1) =0` `⇔ (x + 20)/19 + (x + 20)/17 + (x + 20)/14) = 0` `⇔ (x + 20) (1/19 + 1/17 + 1/14) = 0` `⇔ x + 20 = 0` (Vì `1/19 + 1/17 + 1/14 \ne 0`) `⇔ x = 0 – 20` `⇔ x = -20` Vậy `x = -20` Trả lời
Đáp án: `x=-2` Giải thích các bước giải: `(x+1)/19+(x+3)/17+(x+6)/14=-3` `=>(x+1)/19+(x+3)/17+(x+6)/14+3=0` `=>((x+1)/19+1)+((x+3)/17+1)+((x+6)/14+1)=0` `=>((x+1)/19+19/19)+((x+3)/17+17/17)+((x+6)/14+14/14)=0` `=>(x+1+19)/19+(x+3+17)/17+(x+6+14)/14=0` `=>(x+20)/19+(x+20)/17+(x+20)/14=0` `=>(x+2)(1/19+1/17+1/14)=0` `=>x+2=0` (vì `1/19+1/17+1/14\ne0`) `=>x=-2` Vậy `x=-2` Trả lời
*Lời giải :
`(x + 1)/19 + (x + 3)/17 + (x + 6)/14 = -3`
`⇔ (x + 1)/19 + (x + 3)/17 + (x + 6)/14 + 3 = 0`
`⇔ ( (x + 1)/19 + 1) + ( (x + 3)/17 + 1) + ( (x + 6)/14 + 1) =0`
`⇔ (x + 20)/19 + (x + 20)/17 + (x + 20)/14) = 0`
`⇔ (x + 20) (1/19 + 1/17 + 1/14) = 0`
`⇔ x + 20 = 0` (Vì `1/19 + 1/17 + 1/14 \ne 0`)
`⇔ x = 0 – 20`
`⇔ x = -20`
Vậy `x = -20`
Đáp án:
`x=-2`
Giải thích các bước giải:
`(x+1)/19+(x+3)/17+(x+6)/14=-3`
`=>(x+1)/19+(x+3)/17+(x+6)/14+3=0`
`=>((x+1)/19+1)+((x+3)/17+1)+((x+6)/14+1)=0`
`=>((x+1)/19+19/19)+((x+3)/17+17/17)+((x+6)/14+14/14)=0`
`=>(x+1+19)/19+(x+3+17)/17+(x+6+14)/14=0`
`=>(x+20)/19+(x+20)/17+(x+20)/14=0`
`=>(x+2)(1/19+1/17+1/14)=0`
`=>x+2=0` (vì `1/19+1/17+1/14\ne0`)
`=>x=-2`
Vậy `x=-2`