а) х^2 - 1 = (x-1)(x+1)
б) х^2 + 4х +4 = (x+2)(x+2)
в) 25у ^2 - 4 = 25у ^2 - 2^2 = (5y-2)(5y+2)
г) 36а^2 – 60ав +25в^2 = (6a-5в)(6а-5в)
{(x-1)/(3-2x) ≥ 1/2 ; x² ≤ 25.
{(x-1)/(2x-3) +1/2 ≤ 0 ; x² - 25 ≤ 0.
{(2(x-1)+(2x-3) )/2(2x -3) ≤ 0 ; (x+5)(x-5) ≤ 0 .
{ 4(x-5/4)/4x(x-3/2) ≤ 0 ; (x+5)(x-5) ≤ 0 .
{ (x-5/4)/x(x-3/2) ≤ 0 ; (x+5)(x-5) ≤ 0 .
{ x∈(-∞;0) U [5/4; 1,5) ; x∈[ -5 ; 5] ⇒x∈ [-5;0) U [5/4; 1,5).
ответ : x∈ [-5;0) U [5/4; 1,5).
A) 8x+16x²-16x²+9=2x
8x-2x=-9
6x=-9
x=-1,5
б) x-3x+36x²=11+36x²-25
x-3x=-14
-2x=-14
x=7
B) 36x²-1-36x²-8x=-1
-1-8x=-1
-8x=0
x=0
г) 8x-9x²=40+36-9x²
8x=76
x=9,5