(19n-6n): 4=26 (16m+5m): 18=7 (17n-8n)•13=351

1. (19n-6n):4=26
13n:4=26
13n=26×4
13n=104
n= 104:13
n=8
(13×8):4=26
104:4=26
26=26
2. (16m+5m):18=7
21m=7×18
21m=126
m= 126:21
m=6
(21×6):18=7
126:18=7
7=7
3. (17n+8n)×13=351
25n=351:13
25n=27
n=27:25
n=1,08
(25×1,08 )×13=351
27×13=351
351=351