1) 2x (5x-7) = 2x^-5 2) (x-5) 2=3x^-x+14

Раскроем скобки и приведем подобные члены:

1)

2x (5x - 7) = 2x^2 - 5; 10x^2 - 14x - 2x^2 + 5 = 0; 8x^2 - 14x + 5 = 0; D/4 = 7^2 - 8 * 5 = 49 - 40 = 9; x = (7 ± √9) / 8 = (7 ± 3) / 8; x = (7 - 3) / 8 = 4/8 = 1/2; x = (7 + 3) / 8 = 10/8 = 5/4.

2)

(x - 5) ^2 = 3x^2 - x + 14; x^2 - 10x + 25 - 3x^2 + x - 14 = 0; - 2x^2 - 9x + 11 = 0; 2x^2 + 9x - 11 = 0; D = 9^2 + 4 * 2 * 11 = 81 + 88 = 169; x = (-9 ± √169) / 4 = (-9 ± 13) / 4; x = (-9 - 13) / 4 = - 22/4 = - 11/2; x = (-9 + 13) / 4 = 4/4 = 1;

Ответ:

1) 1/2 и 5/4; 2) - 11/2 и 1.