Помогите 1/4+2,7 4,1*2/5. 2,9-1целую 3/4. Даю 100 балов

Решите задачу:

$\frac{1}{4} + 2,7 = \frac{1}{4} + 2 \frac{7}{10} = \frac{5}{20} + 2 \frac{14}{20} = 2 \frac{19}{20} = 2,95$

$4,1*\frac{2}{5} = 4 \frac{1}{10} * \frac{2}{5} = \frac{41}{10} * \frac{2}{5} = \frac{41*2}{10*5} = \frac{82}{50} = \frac{41}{25} = 1 \frac{16}{25} = 1,64$

$2,9 - 1\frac{3}{4} = 2\frac{9}{10} - 1\frac{3}{4} = 2\frac{18}{20} - 1\frac{15}{20} = 1 \frac{3}{20} = 1,15$