1. а) (2x-3)^2=4x^2-12x+9;

б) (5x-1)*(5x+1)+(5x+1)^2=25x^2-1+25x^2+10x+1=50x^2+10x;

2. 7-2(x+3)=9-6x

7-2x-6=9-6x

-2x+6x=9-7+6

4x=8

x=2.

а) (2x-3)^2=4x^2-12x+9

б) (5x-1)*(5x+1)+(5x+1)^2=25x^2-1+25x^2+10x+1=50x^2+10x

7-2(x+3)=9-6x

7-2x-6-9+6x=0

-8+4x=0

x=8/4

x=2