3х(3х+7)-(3х+1)²=
(y-2)(y+3)-(y-1)=
(p+1)²-(p+2)²=
4x(3x+6)-(3x-5)(3x+5)=
(7-x)(7+x)+(x+3)² если х= -3,5

3х(3х+7)-(3х+1)^2=3x(3x+7)−(9x^2+6x+1)=9x^2+21x−9x^2−6x−1=15x−1;
(y-2)(y+3)-(y-1)=y^2+3y−2y−6−y+1=y^2−5;
(p+1)^2-(p+2)^2=p^2+2p+1−(p^2+4p+4)=p^2+2p+1−p^2−4p−4=−2p−3;
4x(3x+6)-(3x-5)(3x+5)=12x^2+24x−9x^2−15x+15x+25=3x^2+24x+25;
(7-x)(7+x)+(x+3)^2=49+7x−7x−x^2+x^2+6x+9=58+6x
При х= -3,5     58+6х=58+6*(-3.5)=58-21=37.