Ответ:

[tex] {y}^{6} \times ( {y}^{2} ) {}^{ - 1} = {y}^{6} \times {y}^{ -2 } = {y}^{6 + ( - 2)} = {y}^{4} \\ y = - 10 \\ {( - 10)}^{4} = 10000[/tex]