3/4*60 + 1/5*45 = 3*60/4 + 45/5 = 54 км
ОДЗ
x ≥ 0
( - 2x + 3)^2 = x^2
(-2x)^2 - 12x + 9 - x^2 = 0
4x^2 - 12x + 9 - x^2 = 0
3x^2 - 12x + 9 = 0 /:3
x^2 - 3x + 2 = 0
D = 9 - 8 = 1
x1 = ( 3 + 1)/2 = 4/2 = 2
x2 = (3 - 1)/2 = 2/2 = 1
Ответ
1; 2
(y-y1)/(y2-y1)=(x-x1)/(x2-x1)
(y+2)/-8=(x-1)/-4
y+2=2x-2
y=2x-4