8. Решите уравнение: а) -7.x = 49; б) 56.x = -28; в) (x - 4): 4 = 0,25 ; г) (y – 6) : (5 – 2y) = 0,75

а) -7x = 49 x = 49 / (-7) x = -7 б) 56x = -28 x = -28 / 56 x = -1/2 = -0.5 в) (x - 4) / 4 = 0.25 x - 4 = 0.25 * 4 x - 4 = 1 x = 1 + 4 x = 5 г) (y - 6) / (5 - 2y) = 0.75 y - 6 = 0.75 * (5 - 2y) y - 6 = 3.75 - 1.5y y + 1.5y = 3.75 + 6 2.5y = 9.75 y = 9.75 / 2.5 y = 3.9