giup minh voi cam on moi nguoi nhieu October 27, 2020 by Mít Mít giup minh voi cam on moi nguoi nhieu
Đáp án: `a)x=-1` `b) x=2/3` Giải thích các bước giải: `a)2x(x-5)-x(3+2x)=13` `⇔2x^2-10x-3x-2x^2=13` `⇔-13x=13` `⇔x=-1` vậy `x=-1` `b) 9x^2-12x+4=0` `⇔(3x)^2-2.3x.2+2^2=0` `⇔(3x-2)^2=0` `⇔3x-2=0` `⇔x=2/3` vậy `x=2/3` Reply
`a, 2x(x – 5) – x(3 + 2x) = 13` `↔ 2x^2 – 10x – 3x – 2x^2 – 13 = 0` `↔ -13x – 13 = 0` `↔ -13x = 13` `↔ x = -1` `b, 9x^2 – 12x + 4 = 0` `↔ (3x – 2)^2 = 0` `↔ 3x – 2 = 0` `↔ x = 2/3` Reply
Đáp án:
`a)x=-1`
`b) x=2/3`
Giải thích các bước giải:
`a)2x(x-5)-x(3+2x)=13`
`⇔2x^2-10x-3x-2x^2=13`
`⇔-13x=13`
`⇔x=-1`
vậy `x=-1`
`b) 9x^2-12x+4=0`
`⇔(3x)^2-2.3x.2+2^2=0`
`⇔(3x-2)^2=0`
`⇔3x-2=0`
`⇔x=2/3`
vậy `x=2/3`
`a, 2x(x – 5) – x(3 + 2x) = 13`
`↔ 2x^2 – 10x – 3x – 2x^2 – 13 = 0`
`↔ -13x – 13 = 0`
`↔ -13x = 13`
`↔ x = -1`
`b, 9x^2 – 12x + 4 = 0`
`↔ (3x – 2)^2 = 0`
`↔ 3x – 2 = 0`
`↔ x = 2/3`