1) с+(b+3) = c+b+3 = 21+3 = 242) (c+5)+b = c+5+b = 21+5 = 263) с+(b+6) = c+b+6 = 21+6 = 274) (c+15)+b = c+15+b = 21+15 = 365) с+(b+9) = c+b+9 = 21+9 = 306) (c+10)+b = c+10+b = 21+10 = 31
1) с+(b+3) = c+b+3 = 21+3 = 24
2) (c+5)+b = c+5+b = 21+5 = 26
3) с+(b+6) = c+b+6 = 21+6 = 27
4) (c+15)+b = c+15+b = 21+15 = 36
5) с+(b+9) = c+b+9 = 21+9 = 30
6) (c+10)+b = c+10+b = 21+10 = 31