Ответ;DB,DO,OB,hd,jf,yd,jf8%,kg,jg(&jf,if+%,it,hx,or,hy
(1/4 + 3/4х) : 0,45 = 25/36
1/4 + 3/4х = 25/36 * 0,45
1/4 + 3/4х = 25/36 * 9/20
1/4 + 3/4х = 5/16
3/4х = 5/16 - 1/4
3/4х = 5/16 - 4/16
3/4х = 1/16
х = 1/16 : 3/4
х = 1/16 * 4/3
х = 1/12
Пояснения:
0,45 = 45/100 = 9/20 - сократили на 5
25/36 * 9/20 = (5*1)/(4*4) = 5/16
1/4 = 4/16 - доп.множ. 4
Выполняем умножения в скобках
( ( 6000 + 6300) : 60*40+ ( 198000 + 162000) : 20 ) : 40 =
= ( 12300:60*40 + 360000 : 20 ) : 40 = (8200 + 18000) : 40 =
= 26200 : 40 = 655
Ответ: 655
2,4:8:7=24/10:8:7=3/10:7=<span>3/70
</span>Или:
2,4:8:7= <span>0,04285714285</span>
1500: 5, 5, 5, 3, 2,2.7000: 5, 5, 5, 2, 2, 7, 2.3240: 5, 2, 2, 2, 3, 3, 3, 3.<span>4608: 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3.</span>