1
a) (6p-q)^2=36p^2-12pq+q^2
b) (n+1/7m)(n-1/7m)=n^2-1/49m^2
2
a) y(7x-y)+(x-y)^2=7xy-y^2+x^2 -2xy +y^2=5xy-x^2 ghb x=-1 y =1/5
5*1/5*(-1)-(-1)^2=-1-1=-2
b) (16a^4b -8a^3)/8a^2=8a^3(2ab-1)/8a^2=2a^2b-a при а=3 b=1/2
2*1/2*3^2-3=9-3=6
3
x(8-x)-(3-x)(x+3)=7
8x-x^2-9+x^2=7
8x-9=7
8x=16
x=2
4
y^3+(5-y)(25+5y+y^2)= y^3+125-y^3=125
от y не зависит