17 (3x+4) + 13 (5-4x) = 11 (7x-11) + 20

17 (3x + 4) + 13 (5 - 4x) = 11 (7x - 11) + 20;

17 * 3 х + 17 * 4 + 13 * 5 + 13 * (-4 х) = 11 * 7 х + 11 * (-11) + 20;

51 х + 68 + 65 + (-52 х) = 77 х + (-121) + 20;

51 х + 68 + 65 - 52 х = 77 х - 121 + 20;

51 х - 52 х - 77 х = - 121 + 20 - 68 - 65;

-х - 77 х = - 121 + 20 - 68 - 65;

-78 х = - 121 + 20 - 68 - 65;

-78 х = - 101 - 68 - 65;

-78 х = - 169 - 65;

-78 х = - 234;

78 х = 234;

х = 234 : 78;

х = 3.

Проверка:

17 (3 * 3 + 4) + 13 (5 - 4 * 3) = 11 (7 * 3 - 11) + 20;

17 (9 + 4) + 13 (5 - 12) = 11 (21 - 11) + 20;

17 * 13 + 13 * (-7) = 11 * 10 + 20;

221 + (-91) = 110 + 20;

221 - 91 = 130;

130 = 130.

Ответ: х = 3.