Пусть tgx=t
V=90/3=30
2c(9-p²)= 2c(3-c)(3+c)
3k(y²-1)= 3k(y-1)(y+1)
3(x²-25a²)= 3(x-5a)(x+5a)
-2a(y²-a²)= -2a(y-a)(y+a)= 2a(a-y)(y+a)
5x(x²-a²)= 5x(x-a)(x+a)
bc(c²-b²)= bc(c-b)(c+b)