Решите уравнение:
а) 3(-2x + 1) - 2(х + 13) = 7х - 4(1 - x);
б) -4(5 - 2а) + 3(а - 4) = 6(2 - а) - 5а;
в) 8у(4y - 1) - 2у(бу - 5) = 9у - 8(3 + у);
г) 15x + 6x(2 - 3х) = 9x(5 - 2x) - 36.

Решение:


а) 3 • (-2x + 1) - 2 • (х + 13) = 7х - 4 • (1 - x) => -6x + 3 - 2x - 26 = 7x - 4 + 4x => 7x + 4x + 6x + 2x =
= -26 + 3 + 4 => 19x = -19 => x = -1;
6) -4 • (5 - 2а) + 3 • (а - 4) = 6 • (2 - а) - 5а => -20 + 8a + 3a - 12 = 12 - 6a - 5a => 8a + 3a + 6a + 5a =
= 12 + 20 + 12 => 22a = 44 => a = 2;
в) 8у • (4y - 1) - 2у • (бу - 5) = 9у - 8 • (3 + у) => 12у² - 3y - 12у² + 10y = 9y - 24 - 8y => -3y + 10y - 9y + 8y =
= -24 => 6y = -24 => у = -4;
г) 15x + 6x • (2 - 3х) = 9x • (5 - 2x) - 36 => 15x + 12x - 18x² = 45x - 18x² - 36 => 15x + 12x - 45x - 18x² + 18x² =
= -36 => -18x = -36 => x = 2.