Answer:
[tex]x^{3}-\frac{8}{7} xy^{2} -\frac{7}{8}x^{2}y+y^{3}[/tex]
Step-by-step explanation:
[tex](\frac{1}{7} x -\frac{1}{8} y)*(7x^{2} - 8y^{2}) =\frac{1}{7} x*7x^{2} -\frac{1}{7} x*8y^{2}-\frac{1}{8} y*7x^{2} + \frac{1}{8} y*8y^{2}=\\\\=x^{3}-\frac{8}{7} xy^{2} -\frac{7}{8}x^{2}y+y^{3}[/tex]
