1) 24•5=120(руб.) - стоит фотоальбом
2) 120•3=360(руб.) - стоит словарь
3) 120+360=480(руб.)
ответ; За покупку надо будет заплатить 480 руб.
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
5*(3x-y)/6 - (1,5x+y/6) = (15x - 5y)/6 - (3x/2 + y/6) = (15x-5y)/6 - (9x+y)/6 =
(15x-9x - 5y-y)/6= (6x-6y)/6=x-y
1) 5/9 = 15/27 = 25/45 = 40/72
2) 7/6 = 21/18 = 35/30 = 49/42
3) 3/4 = 18/24 = 24/32 = 36/48
4) 2/3 = 19/15 = 14\/21 = 18/27