293. Найдите корень уравнения: a) -7 (0,3x - 8) + 3 (0,4x + 5) = 8; б) 43,2(11/18 x - 7/8) - 25,5(9/17 x - 2/3) = -59,5.

a) -7 (0,3x - 8) + 3 (0,4x + 5) = 8 -2,1x + 56 + 1,2x + 15 = 8 -0,9x + 71 = 8 -0,9x = 8 - 71 -0,9x = -63 x = -63 / -0,9 x = 70 б) 43,2(11/18 x - 7/8) - 25,5(9/17 x - 2/3) = -59,5 432/10 (11/18 x - 7/8) - 255/10 (9/17 x - 2/3) = -595/10 24/10 (11x - 63/4) - 15/10 (9x - 34/3) = -595/10 24/10 * 11/18 x - 24/10 * 7/8 - 15/10 * 9/17 x + 15/10 * 2/3 = -59,5 264/180 x - 168/80 - 135/170 x + 30/30 = -59,5 22/15 x - 21/10 - 27/34 x + 1 = -59,5 (22/15 - 27/34) x = -59,5 + 21/10 - 1 (748/510 - 405/510)x = -595/10 + 21/10 - 10/10 343/510 x = -584/10 x = -584/10 * 510/343 x = -584/1 * 51/343 x = -29784/343 Ответ: a) x = 70; б) x = -29784/343