(x-2)^2 + 8x = (x-1)(1+x)
x^2-2x+4+8x=x+x^2-1-x
x^2-x^2-2x+8x-x+x=-1-4
6x=-5
x=-5/6
= 48c^2-54cd+8cd-9d^2-110cd+40d^2+22c^2-8cd=70c^2-31d^2-164cd
(b^2+8b+16)/(b^2-16) = ((b+4)^2)/((b-4)(b+4)) = (b+4)/(b-4)
Ответ: 4.
В следующий раз грамотнее пишите выражение.
Решение
1) cost = √2/2
t = (+ -)arccos(√2/2) + 2πk, k∈z
t = (+ -)(π/4) + 2πk, k∈Z
2) cos(3π + t) = - 1/2
- cost = - 1/2
cost = 1/2
t = (+ -)arccos(1/2) + 2πn, n∈z
<span>t = (+ -)(π/3) + 2πn, n∈Z</span>
Решение
Ctg (pi/3-1/4x)=5/12
сtg(1/4x - π/3) = - 5/12
(1/4)x - π/3 = arctg(- 5/12) + πk, k ∈Z
(1/4)x = π/3 - arctg(5/12) + πk, k ∈Z
x = 4π/3 - 4arctg(5/12) + 4πk, k ∈Z