4y = 12-3x
y = 3 - 0.75x
всё
(sin(π-a)sin(2π+a))/(tg(π+a)cos(π/2+a)=-cos a
(sin a * sin a)/(tg a * -(sin a)) = -cos a
- sin a/tg a = -cos a
- sin a * cos a / sin a = -cos a
-cos a = -cos a
(-12)^2–15*12+q=0
144–180 = -q
-36=-q
q=36
x^2+15x+36=0
Д=/225–4*1*36=/81=9
х1=(-15+9)/2= –3
х2=(-15-9)/2= –12
Ответ: q=36, второй корень уравнения –3