Умоляю помогите!!!!!!Дам много баллов!!!!!

3)(c-1/7)(1/7+c)=1/7c+c^2-1/49-1/7c=c^2-1/49 4)(3a-b^4)(b^4+3a)=3ab^4+9a^2-b^8-3ab^4=9a^2-b^8 5)(q^11+1/8)(1/8-q^11)=1/8q^11-q^22+1/64-1/8q^11=-q^22+1/64 6)(0.2+x)(x-0.2)=0.2x-0.04+x^2-0.2x=-0.04+x^2 7)(y+5/12)(5/12-y)=5/12y-y^2+25/144-5/12y=-y^2+25/144 8)(a^3b^5-2)(2+a^3b^5)=2a^3b^5+a^6b^10-4-2a^3b^5=a^6b^10-4