1) 3x^2-12=0

2) 2x^2+6x=0

3) 1,8x^2=0

4) x^2+9=0

5) 7x^2-14=0

6) x^2-3x=0

7) (x-2) ^2=3x-8

8 (x-1) ^2=29-5x

9) (x+3) ^2 = - (x-1) ^2

10) 5 (x=2) ^2=-6x-44

11) (-x-1) (x-4) = x (4x-11)

12) 5 (x-2) = (3x+2) (x-2)

1) 3x^2-12=0

3x^2=12

x^2=4

x=+-2

2) 2x^2+6x=0

2x (x+3) = 0

x=0 x=-3

3) 1,8x^2=0

x=0

4) x^2+9=0

x^2=-9

net resheniy

5) 7x^2-14=0

x^2-2=0

x^2=2

x = + - √2

6) x^2-3x=0

x (x-3) = 0

x=0 x=3

7) (x-2) ^2=3x-8

x^2-4x+4-3x+8=0

x^2-7x+12=0

(x-4) (x-3) = 0

x=4 x=3

8) (x-1) ^2=29-5x

x^2-2x+1-29+5x=0

x^2+3x-28=0

(x+7) (x-4) = 0

x=-7 x=4

9) (x+3) ^2 = - (x-1) ^2

x^2+6x+9=x^2-2x+1

8x=-8

x=-1

10) 5 (x-2) ^2=-6x-44

5 (x^2-4x+4) + 6x+44=0

5x^2-14x+64=0

D=14^2-64*4*5<0

net resheniy

11) (-x-1) (x-4) = x (4x-11)

-x^2+4x-x+4=4x^2-11x

5x^2-14x-4=0

D=14^2+4*5*4=276

√D=√276

x1 = (14-√276) / 10

x2 = (14+√276) / 10

12) 5 (x-2) = (3x+2) (x-2)

5=3x+2

3x=3

x=1