Решите уравнение:
а) 5(у + 2/3) - 3 = 4(3y - 1/2);
б) 7(2y - 2) - 2(3y - 3,5) = 9;
в) 21,5(4x - 1) + 8(12,5 - 9х) = 82;
г) 12,5(3x - 1) + 132,4 = (2,8 - 4х) • 0,5;
д) 3x+6/2 - 7x-14/3 - x+1/9 = 0;
е) 1-6x/2 - 2x+19/12 = 23-2x/3.

Решение:


а) 5 • (у + 2/3) - 3 = 4 • (3y - 1/2) => 5y + 10/3 - 3 = 12y - 2 => 15y + 10 - 9 = 36y - 6 => 21y = 7 => у = 1/3;
б) 7• (2y - 2) - 2 • (3y - 3,5) = 9 => 14y - 14 - 6y + 7 = 9 => 8y = 16 => y = 2;
в) 21,5 • (4x - 1) + 8 • (12,5 - 9х) = 82 => 86x - 21,5 + 100 - 72x = 82 => 14x = 3,5 => x = 0,25;
г) 12,5 • (3x - 1) + 132,4 = (2,8 - 4х) • 0,5 => 37,5х - 12,5 + 132,4 = 1,4 - 2х => 39,5х = -118,5 => x = -3;
д) 3x+6/2 - 7x-14/3 - x+1/9 = 0 => 27x + 54 - 42x + 84 - 2x - 2 = 0 => -17x + 136 = 0 => 17x = 136 => x = 8;
е) 1-6x/2 - 2x+19/12 = 23-2x/3 = 6 - 36x - 2x - 19 = 92 - 8x => 30x = - 105 => x = -3,5.