1) 5.9x+2.9x=27.28
8.8x=27.28 | : 8.8
x= 3.1
3) 3.5x+5.1x=24.94
8.6x=24.94 | : 8.6
x=2.9
5) (12-x)*6.5=23.4
78-6.5x=23.4
-6.5x=23.4-78
-6.5x= -54.6 | : -6.5
x=8.4
7) 153 + 0.625y=215,5
0.625y=215-153
0.625y=62 | : 0.625
y=99,2
Х123456789
1 1,2,3,4,5,6,7,8,9
2 2,4,6,8,10,12,16,18
3 3,6,9,12,15,18,21,24,27
4 4,8,12,16,20,24,28,32,36
5 5,10,15,20,25,30,35,40,45
6 6,12,18,24,30,36,42,48,54
7 7,14,21,28,35,42,49,56,63
8 8,16,24,32,40,48,56,64,72
9 9,18,27,36,45,54,63,72
7/3:к=9/2*11/9
7/3:к=11/2
к=11/2:7/3
к=33/14
к=2. 5/14