1.
(7p/(p-1)-1/(p+1)+1)*((p²-1)/p)=((7p*(p+1)-(p-1)+p²-1)/(p²-1))*((p²-1)/p)=
=((7p²+7p-p+1+p²-1)/(p²-1))*(p²-1)/p=((8p²+6p)/(p²-1))*((p²-1)/p)=
(2*p*(4p+3)/(p²-1))*((p²-1)/p=(2*p*(4p+3)*(p²-1))/((p²-1)*p)=2*(4p+3)=2*(4*4+3)=2*19=38
2.
an=-3n-3 S₁₆=?
a₁=-3*1-3=-3-3=-6
a₁₆=-3*16-3=-48-3=-51
S₁₆=(a₁+a₁₆)*n/2=(-6-57)*16/2=-57*8=-456.
Ответ: S₁₆=-456.