ruzanov5656 А) у^2+64-(y-8)^2= у^2+64-(y^2-16y+64)=y^2+64-y^2+16y-64=16y
б)n^4-49-(n^2+7)^2= n^4-49-(n^4+14n^2+49)=n^4-49-n^4-14n^2-49= -14n^2
в) 14x+(x-7)^2=14x+(x^2-14x+49)=14x+x^2-14x+49=x^2+49
г) (6d-1)^2-36d^2=(36d^2-12d+1)-36d^2=36d^2-12d+1-36d^2=1-12d