Question

ПОМОГИТЕ решить $\frac{3}4}-\frac{1}{21} +\frac{1}{4} -\frac{17}{21}$

Answer 1

$\frac{3}{4} - \frac{1}{21} + \frac{1}{4} - \frac{17}{21} = \frac{3 + 1}{4} + \frac{-1 - 17}{ 21} = \frac{4}{4} + \frac{-18}{21} = 1 + \frac{-6}{7} = \frac{7-6}{7} = \frac{1}{7}$