Решите уравнения а) d+1/5=4/7+3/7 f+4/5=4/7+3/7 b+2/5=4/7+3/7 б) c-459=725+275 x-459=725-275 459-z=725-275 в) y:5=250x2 r:100=250x2 m:5=250x3

а) d + 1/5 = 4/7 + 3/7 d + 1/5 = 7/7 = 1 d = 1 - 1/5 = 4/5 f + 4/5 = 4/7 + 3/7 f + 4/5 = 7/7 = 1 f = 1 - 4/5 = 1/5 b + 2/5 = 4/7 + 3/7 b + 2/5 = 7/7 = 1 b = 1 - 2/5 = 3/5 б) c - 459 = 725 + 275 c - 459 = 1000 c = 1000 + 459 = 1459 x - 459 = 725 - 275 x - 459 = 450 x = 450 + 459 = 909 z = 725 - 275 = 450 в) y : 5 = 250 * 2 y : 5 = 500 y = 500 * 5 = 2500 r : 100 = 250 * 2 r : 100 = 500 r = 500 * 100 = 50000 m : 5 = 250 * 3 m : 5 = 750 m = 750 * 5 = 3750