A₁ = a₁₄ - d * (n - 1) = -57 + 3 * 13 = -18
a₃ = a₁ + d * (n - 1) = -18 - 3 * 2 = -24
Y=k*x 4=k*(-8)
x=4,y=-8 k=-1/2
-8=k*4
k=-2
1)=(17,31-12,69)(17,31+12,69)-(29,81-0,19)(29,81+0,19)=(4,62)30-(25,62)30=30(4,62-25,62)=30(-25)=-750..................2)=(7,84-12,16)(7,84+12,16)+(25,66-5,66)(25,66+5,66)=(-4,32)20+20(31,32)=20(-4,32+31,32)=20(-27)=-540