A4 (a+b)^2=a^2+2ab+b2
(4x^5+7y^3)^2=(4x^5)^2+2*4x^5*7y^3+(7y^3)^2=16x^10+56x^5*y^3+49y^6 (Ответ 1)
B1 (a-b)^2=a^2-2ab+b^2
(y-6)^2-y(y-8)=y^2-12y+36-y^2+8y=36-4y
B2 (2x+1)^2-4x^2=7
4^2+4x+1-4x^2=7
4x+1=7
4x=6
x=1,5
C1
(8x+2)^2-16x(4x+1
64x^2+32x+4-64x^2-16x
32x-16x+4
16x+4
16*1/12+4=8