А)
(9/5)х>=0 ¦*(5/9)
x>=0
б)
(5+6x)/2>3
5+6x>6
6x>1
x>(1/6)
4а²(3а-2)-3а(2а-1)²-(2а-5)(2а+5)= 12а³-8а²-3а(4а²-4а+1)-(4а²-25) =
12а³-8а²-12а³ +12а²-3а-4а²+25=
-3а+25=-3*3,3+25=-9,9+25=15,1
<span>(х-22)^2+(х+2)^2=2х^2
x</span>²-44x+484+x²+4x+4=2x²
-40x+488=0
40x=488
x=488/40 = 122/10 = 12.2
Х²-16≥0 ;х²≥16;x1=4 x2=-4 ;x∈[-4;+<span>∞</span>)
<span>решите уравнения
1.log2(10x)-log2(4x+156)=log2 1-7log7 4
</span>log2(10x/(4x+156))=0-7[log2 4]/log2 7
<span>
все верно в условии???
2. log15 (6-35x)*log44(1-2x)=log8 1
</span>log15 (6-35x)*log44(1-2x)=0 ⇔
1)log15 (6-35x)=0 2) log44(1-2x)=0
(6-35x)=1 x=1/7 1-2x=1 x=0
<span>
проверка
</span>log15 (1)*log44(1-2/7)=0 верно log15 (6-0)*log44(1)=0 верно
<span>
3. log2</span>(x+1)+log2(4x+4)=6 одз: x+1>0⇔x>-1
(x+1)(4x+4)=2^6
4(x+1)²=4·2^4
(x+1)²=4²
(x+1-4)(x+1+4)=0 x=3 x=-5∉ одз: x>-1