Решите уравнения.

1) (x+1) (x-1) - (x-2) (x+3) = 0

2) (2x-1) (x+2) - (x-5) (2x+1) = 0

3) 3 (x+1) (x+2) = 9 + (3x-4) (x+2)

4) 5 (2x+3) (x+2) - 2 (5x-4) (x-1) = 12

1) (x²-1) - (x²+3x-2x-6) = 0

x²-1-x²-3x+2x+6=0

-x=-5/:-1

x=5

2) (2x²+4x-x-2) - (2x²+x-10x-5) = 0

2x²+3x-2-2x²+9x+5=0

12x=-3/:12

x=-1/4

3) 3x²+6x+3x+6=9 + (3x²+6x-4x-8)

9x+6=9+2x-8

7x=-5/:7

x=-5/7

4) (10x²+20x+15x+30) - 2 (5x²-5x-4x+4) = 12

10x²+35x+30-10x²+10x+8x-8-12=0

53x=-10/:53

x=-10/53

1) = (x²-1) - (x²+3x-2x-6) = 0

x²-1-x²-3x+2x+6=0

-x=-5

x=5

2) (2x²+4x-x-2) - (2x²+x-10x-5) = 0

2x²+3x-2-2x²+9x+5=0

12x=-3

x=-1/4

3) 3x²+6x+3x+6=9 + (3x²+6x-4x-8)

+9x+6=9+2x-8

7x=-5

x=-5/7

4) (10x²+20x+15x+30) - 2 (5x²-5x-4x+4) = 12

10x²+35x+30-10x²+10x+8x-8-12=0

53x=-10

x=-10/53