Đáp án:
Giải thích các bước giải:
`(2x-3)(x-2)=2x^2+8`
`-> 2x^2 - 7x + 6 = 2x^2 + 8`
`-> 2x^2 - 7x = 2x^2 + 2`
`-> -7x = 2`
`-> x = -2/7`
Vậy `x \in {-2/7}`
`(3x-5)(5x-7)=(5x+2)(3x-2)-2`
`-> 15x^2 - 46x + 35 = 15x^2 - 4x - 6`
`-> 15x^2 - 46x = 15x^2 - 4x - 41`
`-> -46x = -4x - 41`
`-> -42x = -41`
`-> x = 41/42`
Vậy `x\in{41/42}`
`6x-(2x-3)(3x+2)=1`
`-> 11x - 6x^2 + 6 = 1`
`-> 11x - 6x^2 = -5`
`-> x^2 - 11/6x = 5/6`
`-> x^2 - 11/6x + (-11/12)^2 = 5/6 + (-11/12)^2`
`-> x^2 - 11/6x + 121/144 = 241/144`
`-> (x-11/12)^2 = 241/144`
`-> |x-11/12| = sqrt(241)/12`
TH1 :
`x - 11/12 = sqrt(241)/12`
`-> x = (sqrt(241)+11)/12`
TH2 :
`x - 11/12 = -sqrt(241)/12`
`-> x = (11-sqrt(241))/12`
