Геометрия 9 класс

1) x (DR) = 7 - (-2) = 9
y(DR) = |(-8) - 4| = 12
DR = V(x(DR)^2 + y(DR)^2) = V(9^2 + 12^2) = ...

2) S (-7; - 9)
T (5; - 3)
x (ST) = |(-7) - 5| = 12
y (ST) = |(-9) - (-3)| = 6
R = ST = V(x(ST)^2 + y(ST)^2) = V(12^2 + 6^2) = V180
(x - x(S))^2 + (y - y(S))^2 = R^2
(x + 7)^2 + (y + 9)^2 = 180

3) A (-5; -2)

4) y = 1,813x
и так далее (лениво)