(√х-√у)в квадрате+(√х+√у)в квадрате=?

(√х-√у)²+(√х+√у)²=(√х)²-2√х√у+(√у)²+(√х)²+2√х√у+(√у)²=х-2√х√у+у+х+2√х√у+у=2х+2у

d=a2-a1=34-42=-8

an=a1+d(n-1)

a(24)=42-8*(24-1)=-142

s=(a1+an)*n/2=(42-142)*24/2=-1200

b6=b4*q^2

4=2*q^2

q=2; q=-2

b5=8; b5-8

b4=b1*q3

b1=b4/q3

b1=1/2; b1=-1/2