) 9+2х<5
2x<5-9
2x<-4
x<-2
2) 10-3x<4
-3x<-10+4
-3x<-6
x>2
3) 5x-13<7
5x<13+7
x<4
4) 2x+5<3
2x<3-5
x<-2-2
x<-4
1)306х=5202
х=5202:306=17
2)1000у=16000
у=16000:1000=16
4 5/12 - 1 1/2 : (2 1/6 + 8/15) * 1 4/5 = 3 5/12
1) 2 1/6 + 8/15 = 2 5/30 + 16/30 = 2 21/30 = 2 7/10
2) 1 1/2 : 2 7/10 = 3/2 : 27/10 = 3/2 * 10/27 = 1/1 * 5/9 = 5/9
3) 5/9 * 1 4/5 = 5/9 * 9/5 = 1
4) 4 5/12 - 1 = 4 5/12 - 12/12 = 3 17/12 - 12/12 = 3 5/12
3 6/7х - 7/9х + 4 4/63х = 3 54/63х - 49/63х + 4 4/63х = 7 9/63х = 7 1/7х
4 2/9у + 3 1/5у - 2у = 4 10/45у + 3 9/45у - 2у = 7 19/45у - 2у = 7 19/45у - 1 45/45у = 6 64/45у - 1 45/45у = 5 19/45у
Например 51:10=5 остаток 1
например 61:10=6 остаток 1
например 71:10=7 остаток 1
792-264=528
792=264+528
792-528=264
528+264=792