určete koeficienty a, b, c a D
(diskriminant) u následujících kvadratických rovnic, poté určete kořeny:
-x2
– 3x – 2 = 0 |
10x + 9 = -
x2 |
-2x2
– 7x + 15 = 0 |
x2
– 4 (x – 1) = 0 |
3x2
– x – 4 = 0 |
x – 4 = |
5x2
– 14x + 8 = 0 |
x (2x + 5)
= 3 |
-x2
– 6 x + 27 = 0 |
x2 =2
(4 – x) |
-6x2
+ 5x – 1 = 0 |
x (x+15) =
-56 |
-2x2
+ 5x – 2 = 0 |
2x + 5 = |
ŘEŠENÍ
-x2
– 3x – 2 = 0 a=-1, b=-3,
c=-2 D=1 x1=-1,
x2 =-2 |
10x + 9 = -
x2 a=1 , b=10
, c=9 D=64 x1=-9
, x2 =-1 |
-2x2
– 7x + 15 = 0 a=-2 , b=-7
, c=15 D=169 x1=
-5, x2 = |
x2
– 4 (x – 1) = 0 a=1 , b=-4
, c=4 D=0 x=2 |
3x2
– x – 4 = 0 a=3 , b=-1
, c=-4 D=49 x1=
-1, x2 = |
x – 4 = a= 1, b=
-4, c=3 D=4 x1=3
, x2 =1 |
5x2
– 14x + 8 = 0 a= 5, b= -14 , c=8 D=36 x1=
2, x2 = |
x (2x + 5)
= 3 a=2 , b=5 ,
c=-3 D=49 x1=
-3, x2 = |
-x2
– 6 x + 27 = 0 a= -1, b=-6
, c=27 D=144 x1=
9, x2 =-3 |
x2 =2
(4 – x) a= 1, b=2 ,
c=-8 D=36 x1=
-4, x2 =2 |
-6x2
+ 5x – 1 = 0 a=-6 , b=5
, c=-1 D=1 x1=
-½ , x2 = -⅓ |
x (x+15) =
-56 a=1 , b=15
, c=56 D=1 x1=-7
, x2 =-8 |
-2x2
+ 5x – 2 = 0 a= -2, b=5
, c=-2 D=9 x1=2
, x2 = |
2x + 5 = a= 1, b=10
, c=25 D=0 x= -5 |