1
а)x²(x+1)-9(x+1)=0
(x+1)(x²-9)=0
(x+1)(x-3)(x+3)=0
x=-1 x=3 x=-3
б)16/x(x+1)-6/x(x-1)=1/x
ОЗx(x+1)(x-1)≠0⇒x≠0;x≠-1;x≠1
16(x-1)-6(x+1)=(x-1)(x+1)
x²-1-16x+16+6x+6=0
x²-10x+21=0
x1+x2=10 U x1*x2=21
x1=3 U x2=7
в)ОДЗ x-4≥0⇒x≥4
3/(x-4)=4
x-4=0,75
x=4,75
2
а)(x+3)(2x-6)(3x+4)≥0
x=-3 x=3 x=-4/3
_ + _ +
----------------[-3]----------[-4/3]-----------[3]-----------
x∈[-3;-1 1/3] U [3;∞)
б)3/9x+1)-5/(x+2)≤0
(3x+6-5x-5)/(x+1)(x+2)≤0
(1-2x)/(x+1)(x+2)≤0
x=0,5 x=-1 x=-2
+ _ + _
-----------(-2)----------------(-1)--------[0,5]----------------
x∈(-2;-1) U [0,5;∞)
3
25x²-3ax+1=0
D=9a²-100<0<br>(3a-10)(3a+10)<0<br>a=10/3 a=-10/3
a∈(-10/3;10/3)