Smail1987 В:1
х=5


в:3
254+34✓190
__________
930
или 0,777051

Pacanka202 В1. х х–5 х
--- + ------- = --------
6 6–3х 2х–4

х х–5 х
--- + --------- = ---------
6 3(2–х) 2(х–2)

х х–5 х
--- + --------- + --------- = 0
6 3(2–х) 2(2–х)

2х–х^2+2х–10+3х
-------------------------- = 0
6(2–х)

х не равно 2
–х^2+7х–10=0
Д=/49–4•(-1)•(-10) = /9 = 3
х1= (-7+3)/(-2)=2
х2=(-7–3)/(-2)=5
Ответ: 5

В3. 4c–d c–2/cd+d
--------- + -------------- =
2/c –/d /c – /d

4c–d (/c–/d)^2 4c–d
= ---------- + -------------- = --------- + /c–/d
2/c–/d /c – /d 2/c–/d

4c–d+(/c–/d)(2/c–/d)
= ------------------------------- =
2/c–/d

4c–d+2c–/cd–2/cd+d 6c–3/cd
= -------------------------------- = ------------ =
2/c–/d 2/c–/d

3/c(2/c–/d) 1 3
= ---------------- = 3/c = 3/---- = ----
2/c–/d 25 5

B4. (x–5)^4–3(x–5)^2–4=0
Заменим (х–5)^2=а, причём а>=0
а^2–3а–4=0
Д=/9–4•1•(-4)=/25=5
а1=(3+5)/2=4
а2=(3–5)/2=-1 не подходит
(х–5)^2=4
х–5=2; х–5=–2
х1=7; х2=3