Question

21*1/7в квадрате -10*1/7

Answer 1

$21* ( \frac{1}{7} )^{2} -10* \frac{1}{7} = \frac{21*1}{49} - \frac{10}{7} = \frac{3}{7} -\frac{10}{7} =- \frac{7}{7} =-1$