1) (2a+3)(a-3)-2a(4+a)=2a^2-3a-9-(8+2a)*a=2a^2-3a-9-8a-2a^2=2a^2-11a-9-2a^2=-11a-9

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

3) (5-а)(3а+1)-3а(4-а)=14a+5-3a^2-12a+3a^2=2a+5

4) (2-х)(х+2)+(х+2)^2=4-x^2+x^2+4x+4=8+4x