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