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