X1=(2*1+1)*3=9
x2=(2*2+1)*3=15
x3=(2*3+1)*3=21
x4=(2*4+1)*3=27
x5=(2*5+1)*3=33
x6=(2*6+1)*3=39
1. (12m-5m) * 4=252
48m-20m=252
28m=252
m=9
2. (4n+3n)*11=154
44n+33n=154
77n=154
n=2
3. 45:(4m-m)=3
45:3m=3
15m=3
m=0,2
6.( 17n-8n)*13=351
9n*13=351
117n=351
n=3
0,6*m = 3/7*42
0.6m = 18
m = 18/0.6 = 30