Question

Най­ди­те зна­че­ние вы­ра­же­ния 21*(1/7)^2-10*1/7

Answer 1

1) $\frac{1}{7} ^{2} = \frac{1}{49}$
2)27*$\frac{1}{49}$ = $\frac{27}{49}$ 
3)10*$\frac{1}{7}$ = $\frac{10}{7}$
4)$\frac{27}{49} - \frac{10}{7} = - \frac{43}{49}$