<span>13*4,217+0,013-13*1,218
=</span>13*4,217+13*0,001-13*1,218=13(
<span>4,217+0,001-1,218)=
13</span>(
<span>4,218-1,218)=13*3=39</span>
А) 4х^2=121
х^2=121:4
х^2=30,25
х1=5,5 х2=-5,5
б) х(х-5)=0
х1=0 , х2=5
в)4х^2-5х+1=0
(решаю через дискриминант)
Д=б^2-4ас= (-5)^2-4*4*1= 25-16= 9
х1=(-б+√Д)/2а = (5+3)/(2*4)=8/8=1
Х2= (-б-√Д)/2а = (5-3)/(2*4)=2/8=1/4=0,25
4х^2=1
х^2=1/4
х1=1/2
х2= - 1/2
.........................................................
X x
∫5dt>1, 5tl>1, 5x>1,x>1/5,x>0,2 (0,2;∞)
0 0
1 1
∫3dt>9, 3xl >9, 3-3x>9, -3x>9-3, -3x>6, x<6/(-3), x<-2 (-∞;-2)
x x