Найдем значения выражения при известном значении a * b = 170. Тогда получаем: 1 ) ( a * 10 ) * b = a * 10 * b = a * b * 10 = ( a * b ) * 10 = 170 * 10 = 1700 ;2 ) b * ( a * 4 ) = b * a * 4 = a * b * 4 = ( a * b ) * 4 = 170 * 4 = 100 * 4 + 70 * 4 = 400 + 70 * 4 = 400 + 280 = 680; 3 ) a * ( b * 2 ) = a * b * 2 = ( a * b ) * 2 = 170 * 2 = 100 * 2 + 70 * 2 = 200 + 70 * 2 = 200 + 140 = 340; 4 ) ( a * 5 ) * ( b * 2 ) = a * 5 * b * 2 = a * b * 5 * 2 = ( a * b ) * 5 * 2 = ( a * b ) * 10 = 170 * 10 = 1700.