Question

простите выражение:а)(z-7)(z+1)-(z+3)^2 б)2(3k-l)^2+12kl в)y^3+(5-y)(25+5y+y^2)

Answer 1

а)(z-7)(z+1)-(z+3)²=z²-7z-7+z-(z²+9+6z)=z²-7z-7+z-z²-9-6z=-16-12z
б)2(3k-l)²+12kl=2(9k²+l²-6kl)+12kl=18k²+2l²-12kl+12kl=2(9k²+l²)
в)y³+(5-y)(25+5y+y²)=у³+125+25у+5у²-25у²-5у²-у³=125

Answer 2

а)(z-7)(z+1)-(z+3)^2 =z²+z-7z-7-z²-6z-9=-12z-16
б)2(3k-l)^2+12kl =18k²-12kl+2l²+12kl=18k²+2l²
в)y^3+(5-y)(25+5y+y^2)=y³+125-y³=125