1)х+4>0 x>-4
x-5>0 x>5
2)5a-7>0 5a>7
3a+2>0 3a>-2
3)25a+1>0 25a>-1
3a-1>0 3a>1
4)x+3>0 x>-3
x²-x-1>0
D=1+4*1=5
5)5(2+3x)=10+15x=25x=5x
x-1>0 x>1
6)3b(b-c)=3b-3c=bc
<span>sinx+sin5x+sin9x=0</span>
<span>2sin5xcos4x+sin5x=0</span>
<span>sin5x(1+2sin4x)=0</span>
<span>sin5x=0</span>
<span>x=пк/5</span>
<span>2sin4x=-1</span>
<span>sin4x=-0,5</span>
<span>x=-п/24+пк/4</span>
A1=5,d=2
a16=a1+15d
a16=5+15*2=5+30=35
3х-+<span>х²+</span>10=0
-х²+3х+10=0<span>|:(-1)
</span><span>х²-3х-10=0
</span>D=b<span>²-4ac=9-4*1(-10)=49
</span><span>х1= -b-</span>√d/2а=3-7/2=-2
х2=5