(19n-6n)÷4=26 (16m+5m)÷18=7 (17n-8n)×13=351
(19п-6п):4=26; 13п=26*4; 13п=104; п=104:13; п=8
(16м+5м):18=7; 21м=18*7; 21м=126; м=126:21; м=6
(17п-8п)*13=351; 9п=351:13; 9п=27; п=27:9; п=3
1) (19n-6n)÷4=26 13n÷4=26 13n=26×4 13n=104 n=104÷13 n=8 2)(16m+5m)÷18=7 21m÷18=7 21m=18×7 21m=126 m=126÷21 m=6 3)(17n-8n)×13=351 9n=351÷13 9n=27 n=27÷9 n=3