a) 25,4x + 1,47у
25,4 ⋅ 4 + 1,47 ⋅ 3 = 101,6 + 4,41 = 106,01
25,4 ⋅ 10 + 1,47 ⋅ 100 = 254 + 147 = 401
б) 14,34а + 13,56b при a = 1 и b = 10:
14,34 ⋅ 1 + 13,56 ⋅ 10 = 14,34 + 135,6 = 149,94
Ответ: a) 106,01 и 401; б) 149,94