1.x2 + 9x + 20 = 0
(x+5)(x+4)=0
X1=-5
x2=-4
2. 2x2 + 4x = 0
2x(x+2)=0
X1=0
x2=-2
3. 6x2
+ 14x = - 4
6x2+14x+4=0
(3x+1)(2x+4)=0
x1=1/3 x2=2
4. 4x2
-64 = 0
(2x+8)(2x-8)=0
X1=4
x2=-4
5. x2
-2x -24 = 0
(x-6)(x+4)=0
x1=6 x2=-4
6. x2
+ 3x = 0
X(x+3)=0
X1=0
x2=-3
7. 6x2
+ 5x -4= 0
(3x+4)(2x-1)=0
X1=4/3
x2=-1/2
8. x2
- 36= 0
(x+6)(x-6)=0
X1=6
x2=-6
9. x2
- x = 56
(x-8)(x+7)=0
X1=8 x2=-7
10.
3x2 -6x = 0
3x(x-2)=0
X1=0
x2=2
11.
12x2 + 16x - 3 = 0
(6x-1)(2x+3)=0
X1=1/6
x2=-3/2
12.
2x2 + 50 = 0
(2x+10)(2x-10)=0
X1=-5 x2=5
13. x2
+ 8 x +12 = 0
(x+6)(x+2)=0
X1=-6
x2=-2
14. x2
- x = 0
X(x-1)=0
X1=0 x2=1
15.
9x2 + 12x + 4 = 0
(3x+2)(3x+2)=0
X1=-2/3
x2=-2/3
16.
2x2 - 200 = 0
2(x+10)(x-10)=0
(2x+20)(2x-20)=0
X1=-10
x2=10