13. Представьте в виде многочлена: а) (8x+3)²; (10x−7y)²; (4a−b)(16a²+4ab+b²); (4a³−b)(b+4a³); (5m+3)³; 2x(3+8x)−(4x−0,5)².

а)

1. \((8x+3)^2=64x^2+48x+9\).
2. \((10x-7y)^2=100x^2-140xy+49y^2\).
3. \((4a-b)(16a^2+4ab+b^2)=(4a)^3-b^3=64a^3-b^3\).
4. \((4a^3-b)(b+4a^3)=(4a^3)^2-b^2=16a^6-b^2\).
5. \((5m+3)^3=125m^3+225m^2+135m+27\).
6. \(2x(3+8x)-(4x-0.5)^2=6x+16x^2-(16x^2-4x+0.25)=10x-0.25\).

Ответ: \(64x^2+48x+9;\ 100x^2-140xy+49y^2;\ 64a^3-b^3;\ 16a^6-b^2;\ 125m^3+225m^2+135m+27;\ 10x-0.25\).