Question

Помогите пожалуйста!

Answer 1

1. 3x^2-12=0;

3x^2=0+12;

3x^2=12; :3

x^2=4;

x=2.

2. 2x^2+6x=0;

x(2x+6)=0;

2x=0+6;

2x=6;

x=6:2;

x=3.

3. 7x^2-14=0;

7x^2=0+14;

7x^2=14;

x^2=14:7;

x^2=2;

x=1.

4. x^2-3x=0;

x(x-3)=0;

x=0+3;

x=3.

5. 10x+2x^2=0;

x(10+2x)=0;

2x=0-10;

2x=-10;

x=-10:2;

x=-5.

6. 2x^2+9=0;

2x^2=0-9;

2x^2=-9;

x^2=-9:2;

x^2=-4,5;

x=-2,25.

7. x^2-16=0;

x^2=0+16;

x^2=16;

x=8.

8. 9x^2-1=0;

9x^2=0+1;

9x^2=1;

x^2=1/9;

x=1/3.

9. 3x^2+7=12x+7;

3x^2-12x=7-7;

3x^2-12x=0;

x(3x-12)=0;

3x=0+12;

3x=12;

x=12:3;

x=4.