Đáp án`+`Giải thích các bước giải:

 `1, 4x(7x - 5) - 28x(x - 1) = 2x + 10`

`=> 28x^2 - 20x - 28x^2 + 28x = 2x + 10`

`=> 8x = 2x + 10`

`=> 6x = 10`

`=> x = 5/3`

Vậy `x = 5/3`

`2, (4x + 9)^2 - (8x + 3)(2x - 5) = 0`

`=> 16x^2 + 72x  +81 - 16x^2 + 40x - 6x + 15= 0`

`=> 106x + 96 =0`

`=> x = (-48)/(53)`

Vậy `x = (-48)/(53)`

`3, (6x + 3)(6x - 3) - (6x + 7)^2 = 12`

`=> 36x^2 - 9 - 36x^2 - 84x -49 = 12`

`=> -84x - 58 = 12`

`=> -84x = 70`

`=> x= (-5)/6`

Vậy `x=  (-5)/6`

`4, (5x - 2)^2 - (5x + 4)^2 = 8 - 2x`

`=> 25x^2 - 20x + 4 - 25x^2 - 40x - 16 = 8 - 2x`

`=> - 60x - 12 = 8 - 2x`

`=> -58x = 20`

`=> x = (-10)/(29)`

Vậy `x=  (-10)/(29)`

`5, (8x - 9)(7x + 3) + (56x - 2)(x - 1) =0`

`=> 56x^2 + 24x - 63x - 27 +  56x^2 - 56x - 2x + 2 =0`

`=> 112x^2 -97x -25 =0`

`=> 112(x^2 - (97)/(112)x - (25)/(112)) = 0`

`=> x^2 - 2.x (97)/(224) + (9409)/(50176) - (20609)/(50176) = 0`

`=> (x - (97)/(224))^2 - (\sqrt{(20609)/(50176)})^2= 0`

`=> (x - (97)/(224) - \sqrt{(20609)/(50176)})(x - (97)/(224) + \sqrt{(20609)/(50176)}) =0`

`=>` $\left[\begin{matrix} x= \dfrac{97}{244} + \sqrt{\dfrac{20609}{50176}}\\ x = \dfrac{97}{224} - \sqrt{\dfrac{20609}{50176}}\end{matrix}\right.$

Vậy `x = (97)/(244) +- \sqrt{(20609)/(50176)}`

`***`sharksosad