Решите уравнение: а) 3(5х-4)-8х=4х+9 б) 19х-8(х-3)=66-3х в)0,2(0,7х-5)+0,02=1,4(х-1,6) г) 2,7(0,1х+3,2)+0,6(1,3-х)=16,02
Анна Смирнова
3(5х-4)-8х=4х+9
15х-12-8х=4х+9
15х-8х-4х=12+9
3х=21
х=7
19х-8(х-3)=66-3х
19х-8х-24=66-3х
19х-8х+3х=66-24
14х=42
х=42:14
х=3
0.2(0.7х-5)+0.02=1.4(х-1.6)
0.14х-1+0.02=1.4х-2.24
0.14х-1.4х=1-0.02-2.24
-1.26х=-1.26
х=-1.26:-1.26
х=1
2.7(0.1х+3.2)+0.6(1.3-х)=16.02
0.27х+8.64+0.78-0.6х=16.02
0.27х-0.6х=16.02-8.64-0.78
-.33х=6.6
х=6.6:3.3
х=2
4-20х=9-18х+15
-20х+18х=9+15-4
-2х=20
х=-10
Решение во вложении........................
(64*125+128*75)÷800*5000-(300*400+5107*800)÷70 =(8000+9600) : 800 *5000 - (120000+4085600) :70 =
17600 : 800 * 5000 - 4205600 : 70=
22 * 5000 - 60080 =
110000 - 60080 = 49920